Barcelona coach Ronald Koeman believes Lionel Messi is slowly getting back to his best after a brace against Athletic Bilbao.

Messi scored twice, to go with Pedri's goal, at San Mames on Wednesday as Barca recorded a 3-2 victory.

The star has been involved in 10 goals in his past 10 games in all competitions, netting eight and assisting two.

And Koeman feels Messi, who has netted 12 times in 20 appearances this season, is improving.

"Since the first day that I arrived at the club I think Lionel Messi has given everything," he told a news conference.

"I haven’t been surprised by his quality because he's obviously been showing how good he is for years. It's possibly true that he's been less effective than normal which is why there could have been doubts but he's doing a lot better now, he feels comfortable at the moment and he feels up for the challenge.

"That's how I feel. But I think Messi is the one who can answer that best."

Pedri cancelled out Inaki Williams' opener before Messi's double, and Barca moved into third in LaLiga despite Iker Muniain's late goal.

Koeman also praised Ousmane Dembele, who along with Pedri and Antoine Griezmann had a game-high three key passes.

"I think everything starts with the player himself. If the player feels comfortable and feels physically fit he can play well," he said.

"I don't think there's ever been any question about his quality, at least in my opinion, but there have been doubts about his ability to stay fit. At the moment he seems fully fit and I have to think about the programme of games ahead and when we can give him a rest because he hasn't played regularly for quite some time.

"He has to learn how to manage his game time as well. But in terms of the football he can play we know what he can give to the team. He's very good going forward, he attacks with the ball and those are good qualities for us."

Barca, who are seven points behind league leaders Atletico Madrid and have played two more games, visit Granada on Saturday.

Ronald Koeman believes Barcelona demonstrated they are on the right track by overcoming an early setback to win 3-2 at Athletic Bilbao.

Inaki Williams raced clear to put the hosts, who had Marcelino in charge for the first time, in front inside three minutes of Wednesday's LaLiga clash.

However, Barca responded impressively, goals from Pedri and Lionel Messi putting them in front by the break before the latter increased their lead just after the hour mark.

Koeman had to endure a nervy finish after Iker Muniain's 90th-minute finish, but promised his squad will "fight until the last match" in LaLiga after moving up to third in the table.

"The final result is a bit short because we have been superior in many phases," Koeman said, having now recorded three away wins on the spin in LaLiga for the first time in his reign.

"They made it 1-0 and we did not have the defensive coordination, but then we controlled [the game].

"I am happy with the result and with how we have achieved it. We have deserved it. Winning because of our game and our opportunities.

"The teamwork has been phenomenal. We will fight until the last match. There is distance [to go], but we are on the right track." 

Messi will understandably dominate the agenda having scored twice, but Koeman was also quick to praise the performance of Pedri, who completed over 90 per cent of his attempted passes.

The teenage midfielder scored the equaliser, heading in Frenkie de Jong's cutback cross with goalkeeper Unai Simon out of position, while it was his backheeled pass that set up Messi to make it 2-1.

"Pedri is showing despite his youth that he is very mature," the Dutchman said in his post-match interview.

"Messi has always shown his desire but today also with goals. It is very important."

Messi's long-term future at Camp Nou may be unclear but his recent form has shown no lack of commitment to the cause; he has been involved in 10 goals in his last 10 games in all competitions.

Barca are next in action on Saturday, when they visit Granada.

Lionel Messi scored twice as Barcelona ruined Marcelino's first match in charge of Athletic Bilbao with a hard-fought 3-2 triumph at San Mames.

Inaki Williams made an instant impression on Athletic's new boss - appointed following the dismissal of Gaizka Garitano - by scoring inside three minutes for the home team on Wednesday.

Capitalising on a ridiculously high defensive line, the forward ran clear from inside his own half and, after cutting back inside a half-hearted challenge from Clement Lenglet, fired low past Marc-Andre ter Stegen to break the deadlock. 

However, with Messi leading the way, Barca recovered from the setback to turn the game around by the interval, albeit with some help from the hosts.

Unai Simon was tempted out to deal with Messi's seemingly over-hit cross for the equaliser, the alert Frenkie de Jong stretching out to volley the ball back into the middle for Pedri to nod into an unguarded net. 

The Athletic goalkeeper was caught again when his side conceded seven minutes before the break, Pedri the provider as his clever back-heeled assist set up the supporting Messi to pass the ball in, Simon - who had initially rushed out expecting the teenager to shoot - stranded out of position.

Athletic briefly threatened a recovery of their own early in the second half, yet it was always their opponents who carried the far greater threat in attack.

Having seen a goal ruled out for offside and a long-range shot denied by a post, Messi finally scored again when sweeping Antoine Griezmann's square pass home via the underside of the crossbar.

There was late drama when a turnover in possession allowed Alex Berenguer to tee up Iker Muniain for a first-time finish that cut the gap in the 90th minute, but Barca held firm to claim all three points.

Barcelona have given midfielder Carles Alena permission to leave the club this month, with the player expected to move on loan.

The 23-year-old La Masia product has struggled to establish himself under Ronald Koeman this season, with only one of his five appearances across LaLiga and the Champions League coming in the starting XI.

Alena spent the second half of last season on loan at Real Betis and Getafe have been linked with his services on a deal that will likely run until the end of the season.

"Alena has permission from the club to seek his exit," Koeman told a news conference ahead of Wednesday's trip to Athletic Bilbao.

"When everything is done, I will be able to give an opinion, but there are players who can decide to stay or not. He has decided to seek his exit."

Barca's preparations for their visit to San Mames were hit by two positive coronavirus cases among the club staff on Monday.

That forced pre-match training and media duties to be postponed until later on Tuesday, when Koeman's squad were confirmed to have a clean bill of health in terms of COVID-19.

"There are things in life that cannot be controlled," the former Netherlands boss said.

"We have followed the protocol by suspending the training this morning and repeating the PCR tests.

"We could only hope that there were no more positives. Thank goodness that everyone has come out negative and we were able to prepare for tomorrow's game. "

Barcelona head into the match in fifth, 10 points behind leaders Atletico Madrid having played a game more.

Despite a hectic fixture schedule this month, Koeman has not ruled out bringing in reinforcements to bolster an ailing title challenge.

"Any team looks at how the squad can be improved in January," he added.

"I make my plans on seeing the casualties we may have and what players [we need] to bring.

"But if it is not possible, I will have the same players."

Athletic Bilbao have reached an agreement in principle to appoint Marcelino as coach until 2022 after sacking Gaizka Garitano.

The LaLiga club sacked Garitano, who took charge in December 2018, just hours after recording a 1-0 win over Elche on Sunday.

That result sees Athletic sitting ninth in the table, seven points adrift of fifth-placed Barcelona.

Former Valencia boss Marcelino was announced as Garitano's replacement later on Sunday.

Athletic announced they had reached an agreement in principle with Marcelino until 2022.

After more than two years in charge, Marcelino was sacked by Valencia in September 2019.

He helped the LaLiga club win the Copa del Rey in 2018-19.