Kemba Walker is available to play for the first time this season and could feature for up to 20 minutes for the Boston Celtics against the New York Knicks.

Walker has not appeared since the Celtics' Eastern Conference Finals defeat to the Miami Heat in Orlando last year.

The former Charlotte Hornets point guard has been working on strengthening his left knee in an attempt to avoid any further lay-offs in the remainder of the campaign.

Knee soreness contributed to Walker missing 16 of Boston's 72 regular season games in 2019-20, his first year after leaving Charlotte, so the team are hoping to avoid a repeat.

Walker was listed as questionable this week for the first time all season and was then upgraded to available on Sunday ahead of the game at TD Garden at 1300 ET.

Coach Brad Stevens subsequently confirmed Walker would have a restriction of around 20 minutes.

The 8-3 Celtics are still without Jayson Tatum, among others, due to NBA health and safety protocols in the aftermath of the team's coronavirus crisis.

Boston had three consecutive games postponed and their practices cancelled - contributing to Walker's delayed return - before beating the Orlando Magic 124-97 on Friday.

Walker averaged 20.4 points per game last season, trailing only Tatum (23.4) for the Celtics, while also contributing 4.8 assists, behind just Marcus Smart (4.9).

The 30-year-old's scoring dropped slightly to 19.6 in the postseason - putting Tatum (25.7) and Jaylen Brown (21.8) ahead of him - but he led the team in playoff assists with 5.1 per game.

Alpine have appointed Davide Brivio, the former boss of MotoGP team Suzuki Ecstar, as their racing director.

Renault announced the departure of team principal Cyril Abiteboul on Monday ahead of their rebrand to Alpine for the 2021 Formula One campaign, and now they have added new blood.

Brivio was linked to F1 after quitting his post with Suzuki Ecstar, who won the team and rider championships in last year's MotoGP season.

An Alpine statement read: "Davide Brivio joins Alpine F1 Team as racing director.

"We are delighted to confirm Davide Brivio will strengthen our team ahead of the 2021 Formula One season. His specific role and responsibilities will be announced in the coming weeks.

"Davide will report to the Alpine CEO Laurent Rossi.

"Davide joins Alpine F1 Team with a wealth of experience and success following more than 20 years in the MotoGP world championship.

"We look forward to welcoming Davide as we start the next stage of our Formula One journey."

Alpine's driver line-up is made up of Frenchman Esteban Ocon and former two-time champion Fernando Alonso.

Robert Lewandowski became the first player to hit 21 goals in the first half of a Bundesliga campaign with his opener for Bayern Munich against Freiburg.

Gerd Muller previously held the record of 20 goals, with the Bayern great having achieved the feat in 1968-69.

Lewandowski matched that haul on January 8, scoring in a 3-2 defeat to Borussia Monchengladbach.

On Sunday, in Bayern's 16th league game of the 34-match campaign, the 32-year-old overtook Muller by slotting home at the culmination of a superb Bayern move in the seventh minute.

It also brought up Lewandowski's fifth goal in his last four games against Freiburg.

Prolific in attack, it is at the other end where Hansi Flick's Bayern side have struggled this season.

Heading into Sunday's game at the Allianz Arena, the Bavarian side had 33 points – they last had as many points after 15 matches in 2017-18 - yet their 24 goals conceded after 15 fixtures was more than in any season since 1981-82 (25).

Lewandowksi scored 34 times in the league last season, six shy of Muller's Bundesliga record of 40 (1971-72), but the Poland star now looks well on course to challenge that tally.

Stefano Pioli confirmed Milan will consider adding further to their squad in January amid speculation Mario Mandzukic is set to join the club.

Mandzukic – who previously played in Serie A with Juventus – is a free agent after terminating his contract with Al-Duhail by mutual consent in July.

The Rossoneri are reportedly going to sign the Croatian striker on an 18-month deal, boosting their forward options as they look to maintain their push to win the league for the first time in a decade.

Pioli was not willing to discuss individual names at his pre-match news conference ahead of Monday's trip to Cagliari but did admit the club are ready to act if the right player becomes available.

"I don't want to and cannot comment on players that I don't have," he told the media. "I have a lot of confidence in the club and the management team. I leave that task to them.

"We know that if there is the possibility of strengthening the team, we will do it. We will be ready in January if there is the possibility of improving this group." 

Milan have already made one signing in the mid-season transfer window, midfielder Soualiho Meite arriving on loan from Torino.

"Meite makes a department that already had good solidity even more competitive," Pioli said of the new recruit.

"I really liked the move. We have combined quality and quantity. I also liked how he spoke, saying he was ambitious. To join our group, you have to be like that."

The Serie A leaders head to Cagliari without Hakan Calhanoglu and Theo Hernandez, both players currently isolating after testing positive for coronavirus.

Pioli admits it is a blow to be without the influential duo – they are also set to miss next Saturday's home fixture with Atalanta – but is confident he has the quality within his squad to cope with such situations during the course of the season.

"They are important absences, but this season is like that," the Milan boss said. "There are critical issues that can come at any moment, so we must always be prepared and attentive.

"The quality of the players that I will have available tomorrow will certainly make us have a good match.

"We are prepared, that's why I expect the players to always be ready. We can all be decisive and help the team."

A further 25 players have been forced into hard lockdown for two weeks prior to the Australian Open, tournament organisers have confirmed.

Tennis' season-opening grand slam was plunged into crisis on Saturday when it was announced 47 players would be consigned to their hotel rooms for 14 days and not eligible to practise.

Officials said the protocols were as a result of two passengers testing positive for coronavirus on a flight from Los Angeles that arrived on Friday morning, along with another passenger who flew in from Abu Dhabi.

That affected 24 players aboard the LA flight and 23 on the plane from Abu Dhabi, while another positive test for a passenger arriving in Melbourne from Doha on Saturday morning has taken the total number of players affected to 72.

A statement from the Australian Open read: "One positive COVID-19 test has been returned from a passenger on a charter flight into Melbourne from Doha which arrived at 5.30am on January 16.

"The passenger is not a member of the playing contingent and had tested negative before the flight.

"There were 58 passengers on the flight, including 25 players. All are already in quarantine hotels.

"The 25 players on the flight will not be able to leave their hotel room for 14 days and until they are medically cleared. They will not be eligible to practise."

About 1,200 players and staff have been arriving in Melbourne on sparsely populated aeroplanes ahead of the delayed Australian Open, which is due to get under way on February 8.

Speaking on Saturday, Tennis Australia CEO Craig Tiley insisted the tournament would be going ahead despite the chaos and the lack of preparation time for many of the playing contingent.

"It's not something we wanted to happen," he told The Today Show. "We were hoping every flight would be okay. We're in this situation, we have to deal with it.

"The Australian Open is going ahead and we'll continue to do the best we can possibly do to ensure those players, who are not in a great position, find it somewhat acceptable.

"We're planning on February 8, we do have that buffer time in there. We're looking forward to welcoming fans to the Australian Open.

"Ticket sales have been going well, we've got two weeks of great tennis and our intention is to continue with those dates."

England lost early wickets in their run chase but remain on course for victory in the first Test against Sri Lanka, finishing day four on 38-3 in pursuit of a target of 74. 

Having battled hard to make 359 all out in their second innings, Sri Lanka gave themselves a glimmer of hope when Lasith Embuldeniya quickly removed England openers Dom Sibley and Zak Crawley. 

The run out of captain Joe Root, who was called through for a single that was never on before falling over as he dived to unsuccessfully make his ground, left the tourists teetering at 20-3. 

However, Jonny Bairstow and Dan Lawrence steadied the nerves, seeing England through to stumps without any further setbacks. The duo will resume on day five needing a further 36 to seal the series opener. 

Sri Lanka will be left cursing their first-innings shortcomings with the bat, particularly after a second Test hundred from Lahiru Thirimanne underpinned a far-improved display second time around. 

England did remove nightwatchman Embuldeniya early but were made to work hard for wickets after that, Jack Leach the pick of the attack as he finished with figures of 5-122. 

Sam Curran eventually ended Thirimanne's defiance when the opener had 111 to his name, while the hosts were still in deficit when stand-in captain Dinesh Chandimal edged Dom Bess (3-100) to Root at first slip.  

The same bowler accounted for Niroshan Dickwella, who made 29, but Angelo Mathews proved to be a familiar thorn in England's side. 

Wicketkeeper Jos Buttler secured his first stumping in Test cricket as some smart glovework ended a lively cameo from Dilruwan Perera (24), while Mathews was the last man out midway through the final session.  

The former Sri Lanka skipper had battled for nearly six hours before Leach tempted him into a leaden-footed drive, ending his resistance on 71. England appeared frenetic at the start of their chase on a dry, turning surface, but will still be confident of completing the job on Monday.

TON-DERFUL MOMENT FOR THIRIMANNE

Thirimanne's previous Test century also came at the same venue; he made 155 not out against Bangladesh back in March 2013. The left-handed opener may not have featured in this match had captain Dimuth Karunaratne not been ruled out with a fractured thumb, but he seized his opportunity.

In total, he faced 251 deliveries and hit 12 boundaries, helping at least restore some pride for Sri Lanka after they had been dismissed for 135 on a dismal opening day.

LEACH STICKS TO HIS TASK

Leach had not played in a Test since November 2019, since when an illness and the COVID-19 pandemic has restricted him to just two first-class appearances. The left-arm spinner could be forgiven for a little rustiness, then.

However, he stuck manfully to his task during the innings, sending down 41.5 overs to claim his second five-wicket haul in Tests. His other also came against Sri Lanka, at Pallekele back in November 2018.
 

Khabib Nurmagomedov could be tempted to make a comeback if a lightweight rival impresses him at UFC 257, Dana White has revealed. 

The undefeated Khabib announced his retirement after beating Justin Gaethje to unify the lightweight division at UFC 254 last year, his first outing since the death of his father and coach Abdulmanap Nurmagomedov.

However, White raised the prospect that the Russian may return for one more bout - if he likes what he sees out of a potential opponent next week. 

That includes former foes Conor McGregor and Dustin Poirier, who meet in the main event on Fight Island. Dan Hooker and Michael Chandler do battle on the same bill, with the winner potentially coming under consideration. 

Charles Oliveira is also an option, having apparently grabbed Khabib's attention during his victory over Tony Ferguson at UFC 256 in December. 

"The thing with him is, when you make the decision to retire, I knew he made the decision under unbelievable emotional stress," White told the media after Max Holloway's victory over Calvin Kattar in Abu Dhabi. 

"His dad had died, he got hurt during that camp and couldn't train right, couldn't cut weight right. All the things he went through and then he went out and performed how he performed, then made that decision that night.  

"Listen, you're not tying anything up. Go home, spend some time with your family. Heal up, think about it. 

"Then he and I got together, and he said: 'I want to see if somebody really blows me away and impresses me next week'. 

"You've got the co-main event and the main event, while Oliveira looked awesome against Tony Ferguson - that's an interesting fight for him. 

"We will see what these guys do this weekend. I think it's fun - do you guys not want to see Khabib fight again? Hopefully, he sticks around and does one more." 

However, White made clear that Georges St-Pierre is not on the shortlist of potential opponents. 

"No, GSP never came up. He's not interested in that fight and, from what I hear today, neither is GSP. That's over," he said.

Milan have announced Hakan Calhanoglu and Theo Hernandez have tested positive for COVID-19.

The two cases were discovered following swab tests carried out on Saturday, with the club immediately informing the health authorities upon learning the results.

Both players are asymptomatic and the rest of the squad tested negative, Milan confirmed in a statement released on Sunday.

Calhanoglu and Hernandez are now isolating at home, leaving Milan without the duo for some key fixtures coming up in January.

The Serie A leaders - who have lost just once in league action this season so far - visit Cagliari on Monday, then host Atalanta at San Siro next Saturday.

There is also a Coppa Italia quarter-final clash with rivals Inter looming on the horizon, that tie due to be played on January 25. 

A-League new boys Macarthur went top of the table with a 2-1 win at Newcastle Jets on Sunday.

Loic Puyo was the star for the visitors, opening the scoring in the eighth minute before teeing up Matt Derbyshire for Macarthur's second 15 minutes later.

Sandwiched between those goals was a VAR decision that denied Jason Hoffman an equaliser for the Jets, ruling him to have strayed offside.

They did pull one back through Valentino Yuel in the 42nd minute but could not complete the comeback as the Jets' winless start to the season continued.

Macarthur are a point ahead of Central Coast Mariners at the top but have played two games more.

Shardul Thakur and Washington Sundar halted Australia's momentum before India were bowled out for 336 on a frustrating day for the hosts in the fourth Test at the Gabba.

Australia appeared on track to clean up India's batting line-up and maintain a healthy lead on day three of the final match after leaving the tourists in a perilous position of 186-6, but unheralded pair Shardul (67) and Sundar (62) put on a remarkable 123-run stand.

Josh Hazlewood's five-wicket haul finally helped put an end to India's stubborn resistance – Australia heading into their second innings with a 33-run advantage on Sunday.

David Warner (20 not out) and Marcus Harris (1 not out) saw out the remaining half-hour of play to lead Australia to 21-0 at stumps, a lead of 54 runs, as Tim Paine's side face a race against time to win the Test and reclaim the Border-Gavaskar trophy.

After rain wreaked havoc on Saturday, India resumed 62-2 in response to Australia's first-innings 369 in Brisbane, where Hazlewood (5-57) and Mitchell Starc (2-88) managed to claim the prized scalps of Cheteshwar Pujara (25) and captain Ajinkya Rahane (37) in the morning session.

Hazlewood removed Mayank Agarwal (38) with the second delivery after lunch, and the Australia star almost dismissed Rishabh Pant (23) to leave India 186-6.

But Shardul and Sundar combined to sensationally thwart Australia, who toiled tirelessly before eventually bowling out India.

Star Australia opener Warner then raced out the blocks with a quick-fire 20 runs, including three boundaries, to navigate a tricky end to the day.

India duo come to the rescue

A remarkable seventh-wicket stand kept Australia at bay and clawed India within touching distance of the hosts' first-innings total.

It was an unlikely pairing that rescued India – Sundar celebrating a half-century on his Test debut, while Shardul also raised his bat for a maiden Test fifty.

Hazlewood huffs and puffs

For the second time in the blockbuster series, Hazlewood recorded a five-for against India.

It was far from easy for Australia, but Hazlewood battled as Pujara, Agarwal, Pant, Navdeep Saini (5) and Mohammed Siraj (13) fell victim to the fast bowler.

A little before the midway point of the season, heading into Sunday's Derby d'Italia, you could argue Inter have Juventus just where they would have wanted them.

Antonio Conte was brought to San Siro in 2019 and strongly backed in the transfer market with the primary aim of ending the dynasty he launched back in 2011-12 in Turin.

Juve have won every Scudetto since then but are four points behind Inter having played a game less.

Unfortunately for Conte, the Nerazzurri aren't the only side with designs on ripping away the Bianconeri's long-held crown.

Milan remain top of the table despite succumbing to a 3-1 defeat to Juve earlier this month, where they were subjected to arguably the most authoritative display of the fledgling Andrea Pirlo era.

Nine points separate Milan from Atalanta, Napoli and Lazio in fifth, sixth and seventh. Like fourth-place Juve, the former two have a game in hand on the leaders.

Inter are their local rival's nearest challengers, three points from the top and three better off than third-place Roma, who were left with wounded pride by Friday's 3-0 derby defeat to Lazio.

Struggles for consistency and congested title races can be seen across Europe as the effects of truncated pre-seasons and packed schedules continue to shake out.

However, the firepower up front for Inter and Juve provides a strong case for both breaking clear of the pack, while promising a thrilling high-stakes shootout at San Siro.

Lukaku-Martinez partnership brings joy

Conte's second and final season in charge of Chelsea in 2017-18 was soured before kick-off as Manchester United beat him to the signature of Romelu Lukaku.

It was clear that state of affairs did little for either man by the time they finally came together at Inter before the start of last season.

Had Lukaku ranked himself as being among the top five strikers in world football, as he did last month, during the 2019 transfer window, plenty would have sniggered.

But the big Belgian has put a patchy spell at Old Trafford behind him to shine at San Siro.

Since the start of last season, Lukaku has 51 goals in all competitions - placing him fourth among players across Europe's top five leagues during that period, in between Lionel Messi in fifth and a certain prospective weekend opponent who is five goals better off.

While not quite as prolific, Argentina international Lautaro Martinez has been a more than able accomplice, racking up 31 in 73 matches over the past season and a half.

Nevertheless, despite this mountain of goals and Inter being Serie A's top scorers, there is a sense that Conte's front two could be more clinical.

No player in the big five leagues with 25 goals or more to their name since the beginning of 2019-20 has a lower shot conversion rate than Martinez's 12.4 per cent.

While Lukaku's conversion rate in 2020-21 is comparatively healthier at 27.9 per cent, in Serie A alone his nine goals from open play come in below an expected goals (xG) figure of 9.8 (Lukaku's three converted penalties do not figure in Opta's xG calculations).

The concern for Conte is that this relative wastefulness takes a heavier toll on the big occasion.

Inter crashed out of the Champions League after winning a solitary group match and have failed to win any of their four Serie A matches so far against last season's top six - a run continued by the raucous 2-2 draw with Roma last time out.

Ronaldo finds ideal foil in Morata

An obvious fear from an Inter perspective is that issues Martinez and Lukaku might have on the grandest stages will only be magnified by comparison to who they face this weekend.

No man in the 21st century has hit the heights of goalscoring obsession known by Cristiano Ronaldo.

Even if Juventus do not have the rampaging version that thrilled at Manchester United and Real Madrid, Ronaldo is raging against Father Time with utter conviction when it comes to putting the ball in the net.

Only Robert Lewandowski - way out in front on 78 - has more than the Portugal great's 56 in the big five leagues from August 2019 onwards.

Among that group of attackers with 25 goals or more, Ronaldo has fired off the most shots with 354. Messi (329) and Lewandowski (297) are not particularly close behind.

Chillingly for opponents, he has found much greater efficiency this season. Ronaldo's shot conversion rate is 23.5 per cent in 2020-21 so far, a 10 per cent increase on the prior campaign. His 11 open-play goals in Serie A have an xG value of 7.9.

If there is a new level of serenity to Ronaldo's play, part of the credit can perhaps go to the man alongside him. 

Alvaro Morata was the third corner of the tangled Lukaku-Conte transfer triangle back in 2017, his time at Chelsea proving to be as sapping as Lukaku's at United. A loan to Atletico Madrid arrived midway through 2018-19. 

Despite that move being made permanent, another loan back to Juventus came prior to the current campaign. 

Under his old team-mate Pirlo, Morata looks like a player reborn, scoring 11 times in all competitions. Only four of those have been in Serie A but his seven assists over the course of the campaign are already more than he managed in the past two completed seasons - casting him as the ideal supporting act to Juve's indisputable lead performer. 

One of the best five in the world, one of the greatest of all time, Argentina's next superstar striker or the quiet man from Madrid. On Sunday, one of them is set to step forward and add a key twist to a gripping Scudetto race.

James Harden made NBA history on his Brooklyn Nets debut after dazzling with a triple-double in the 122-115 win against the Orlando Magic.

Harden became the first player in NBA history to post a 30-point triple-double in his bow for a new team after the Nets outlasted the Magic on Saturday.

Former MVP Harden – who swapped the Houston Rockets for the Nets in a blockbuster trade on Thursday – finished with 32 points, a franchise-record 14 assists, 12 rebounds and four steals.

The eight-time All-Star also became the seventh player in NBA history with a triple-double in their team debut, joining Russell Westbrook, Elfrid Payton, Lewis Lloyd, John Shumate, Nate Thurmond and Oscar Robertson.

Reuniting with former Oklahoma City Thunder team-mate Harden, Durant led the way with a game-high 42 points as the Nets improved to 8-6 following a third consecutive win.

Durant also made franchise history for most consecutive 25-plus point games with nine.

Lillard inspires Blazers

Damian Lillard had a game-high 36 points as the Portland Trail Blazers topped the Atlanta Hawks 112-106. Double-doubles from Trae Young (26 points and 11 assists) and Clint Capela (25 points and 15 rebounds) were not enough for the visiting Hawks.

Shake Milton put up 28 points off the bench in the Joel Embiid-less Philadelphia 76ers' narrow 106-104 loss to the Memphis Grizzlies. Ben Simmons fell just short of a triple-double after recording 11 points, 16 rebounds and nine assists.

Christian Wood scored 24 points and collected 18 rebounds as the shorthanded Rockets went down 103-91 to the San Antonio Spurs.

Derrick Rose was efficient in the Detroit Pistons' 120-100 upset of the Miami Heat. He was eight-of-12 shooting from the field, while making three of his five three-point attempts for 23 points in 21 minutes.

Covington struggles

While the Trail Blazers won, Robert Covington failed to get going shooting-wise after collecting 10 rebounds. He was one-of-13 from the field and just one-of-seven from beyond the arc for three points in 28 minutes.

A championship winner with the Los Angeles Lakers last season, veteran Rajon Rondo was scoreless for the Hawks. Rondo missed all three of his field-goal attempts in nine minutes of action.

Morant returns in style

Ja Morant sprained his ankle on December 28 but the Grizzlies star made his comeback following an eight-game absence. Morant had 17 points, including this alley-oop.

Saturday's results

San Antonio Spurs 103-91 Houston Rockets
Brooklyn Nets 122-115 Orlando Magic
Toronto Raptors 116-113 Charlotte Hornets
Detroit Pistons 120-100 Miami Heat
Memphis Grizzlies 106-104 Philadelphia 76ers
Portland Trail Blazers 112-106 Atlanta Hawks
Indiana Pacers-Phoenix Suns (postponed)

Pacers at Clippers

The Indiana Pacers (8-4) will visit the in-form Los Angeles Clippers (9-4) – who have won three straight games – on Sunday.

Brooklyn Nets superstar James Harden revelled in his record-setting debut, while head coach Steve Nash heaped praise on the former NBA MVP.

Harden became the first player in NBA history to post a 30-point triple-double in his bow for a new team after the Nets outlasted the Orlando Magic 122-115 on Saturday.

Eight-time All-Star Harden swapped the Houston Rockets for the Nets in a blockbuster trade on Thursday, and his first game in a Brooklyn jersey resulted in 32 points, a franchise-record 14 assists, 12 rebounds and four steals.

Afterwards, Harden said: "It felt really good [to get the win]. The guys got after it.

"Individually, I've got to stop turning the basketball over, but that comes with chemistry, that comes with practice, that comes with watching film.

"So, first game I'm glad to get a win and we've just got to keep going."

On the record, Harden was asked what it meant, and he told YES: "Nothing, I'm just happy we came away with the win. Those stats don't mean anything."

"When you're paying with really, really good players, it's pretty easy," Harden said. "For me, I just gotta learn reads, learn where guys like the ball, just learn our personnel individually so once I get that, the turnovers will cut down, I can be more efficient."

Disgruntled in Houston as he eyed an exit from the Rockets, Harden arrived in Brooklyn out of form, but the sharpshooter showed what the Nets are getting in a super team that also consists of Kevin Durant and Kyrie Irving.

Harden was eight-of-18 from the field and three-of-10 shooting from three-point range in 40 minutes, while he also had nine turnovers.

First-year coach Nash, who now leads a genuine championship contender, hailed Harden post-game.

"I can't say I'm surprised," Nash said. "We had a pretty big simple size of him doing that [for] however many years in he's been in the league. But it's still not easy. He's still not in his best condition yet, he's joined a new group.

"Basically no practice time, and figured it out on the fly. He had a bunch of turnovers just because he's new to the team and the group and you’re thrown out there in an NBA where the other team is an excellent coached-basketball team....But all the things he did on the floor were incredible for his first game."

Reuniting with former Oklahoma City Thunder team-mate Harden, Durant led the way with a game-high 42 points as the Nets improved to 8-6 following a third consecutive win.

Durant also made franchise history for most consecutive 25-plus point games with nine.

"James, he played the same way he always played, to be honest," Durant said. "He played the same way he was playing in Houston, being a pass-first guard, trying to get guys good looks. He played the same way.

"Coach put him at the point, I think that's his natural position, is point and combo guard. For him to get 14 assists, 12 rebounds for us at the point guard was key."