Thomas Muller returned to training at Bayern Munich on Thursday after the COVID-19 positive test that caused him to miss the Club World Cup final.

The all-action attacking midfielder was dealt his coronavirus blow just hours before Bayern beat Tigres UANL 1-0 to be crowned club world champions in Qatar on February 11, forcing him to self-isolate.

After two weeks away from the squad, and now clear of the virus, Muller was back at the club's training headquarters to be put through his paces.

Bayern announced on their website: "Muller was able to train at Sabener Strasse again on Thursday for the first time after a period self-isolating at home due to testing positive for COVID-19.

"Following final medical tests in the morning, the 31-year-old completed an individual session on the pitch alongside team training under the guidance of fitness boss Prof Dr Holger Broich."

Muller is enjoying a stellar season and is one of just six players from Europe's 'top five' leagues to have reached double figures both in goals and assists across all competitions.

He has 13 goals and 11 assists so far, and has created 81 chances in all.

Borussia Dortmund's Jadon Sancho is the only other player from the Bundesliga to achieve the double to date, after 10 goals and 12 assists.

Lagging some way behind Muller in the Bayern ranks is Serge Gnabry, who has managed only six goals and two assists in 28 appearances, figures that are also significantly down on what team-mates Leroy Sane (G: 8, A: 8) and Kingsley Coman (G: 6, A: 11) have achieved.

Gnabry has had more playing time than his attacking midfield colleagues Sane and Coman, and he began the campaign with a hat-trick against Schalke in Bayern's opener.

The former Arsenal youngster was substituted off in the Club World Cup final because of a torn muscle in his left thigh.

Bayern said on Thursday that Gnabry had undergone intensive rehabilitation in recent days and was able to resume training with Hansi Flick's squad.

That may see him come into contention, perhaps along with Muller, for Saturday's Bundesliga home clash with Cologne.

Serge Gnabry is set for a spell on the sidelines after suffering a muscle tear in his left thigh, Bayern Munich have confirmed.

Germany international Gnabry was taken off in the 64th minute of Bayern's 1-0 Club World Cup final victory over Tigres UANL on Thursday.

No time frame for the 25-year-old's return was provided by the Bundesliga champions, who are already without Thomas Muller after he tested positive for coronavirus in Qatar.

An official club statement read: "For the time being, Bayern will have to do without Serge Gnabry.

"The attacker suffered a muscle tear in his left thigh in yesterday's Club World Cup final against Tigres. This was the result of an examination by the medical department of Bayern."

After winning the Club World Cup, Bayern return to Bundesliga action at home to Arminia Bielefeld on Monday.

They take on Lazio in the first leg of their Champions League last-16 tie on February 23 and face Borussia Dortmund in Der Klassiker on March 6.

Gnabry has scored six goals and supplied two assists in 28 appearances in all competitions for Bayern this season.

Robert Lewandowski (106) is the only Bayern player to have had more efforts on goal than Gnabry (63) this season, but his shot conversion rate of 9.5 per cent is one of the worst in the squad.

Among players for the Bavarian giants to have attempted at least 20 shots, Corentin Tolisso (8.3 per cent) is the only player with a worse shot conversion rate than Gnabry.

Serge Gnabry did not suffer a serious injury during Bayern Munich's 2-1 victory over Freiburg, Hansi Flick has confirmed.

Germany international Gnabry sat out last weekend's loss to Borussia Monchengladbach with a shin problem but played 90 minutes in the shock penalty shoot-out loss to Holstein Kiel in the DFB-Pokal on Wednesday.

He had to be replaced after 28 minutes at the Allianz Arena on Sunday but Flick is not expecting to be without the winger for a prolonged period.

"The injury is not serious, I have heard from the doctors. The muscle in his back cramped up," said the Bayern boss.

Bayern were leading when Gnabry departed thanks to Robert Lewandowski's 21st goal of the season, a record for the first half of a Bundesliga season, surpassing Gerd Muller's 20 in 1968-69.

Nils Petersen equalised for Freiburg in the 62nd minute, scoring just 28 seconds after coming on as a substitute. His Bundesliga record for goals after being subbed on now stands at 28.

But Leroy Sane, who replaced Gnabry in the first half, set up Thomas Muller - who registered his 125th top-flight assist on Lewandowski's opener - for the winner.

Sane was also on target against Kiel and Flick has been pleased to see him improving after a tough start to life with Bayern following his move from Manchester City.

"I don't like singling out individual players but he did very well and did things the team would like to see from him," said Flick.

"We saw good development. He proved today that he is always good for an assist or a goal."

With RB Leipzig having been held to a 2-2 draw by Wolfsburg on Saturday, reigning Bundesliga champions Bayern opened up a four-point lead at the summit.

Flick said: "I'm not interested in the table at the moment. We have to look at ourselves and be focused on Augsburg and Schalke as we are today.

"It's good to have achieved a four-point lead, that is extremely important. For us, only our results count."

Bayern Munich have been knocked out of the DFB-Pokal on penalties by second-tier side Holstein Kiel following a 2-2 draw after extra time.

The Bavarian giants had reached the last 16 stage in each of the previous 19 seasons and had lifted the cup in the last two of those, but they were stunned by Kiel in Wednesday's clash at Holstein-Stadion.

Leroy Sane had Bayern on the brink of a place in the next round with his sublime free-kick early in the second half after Fin Bartels had earlier cancelled out Serge Gnabry's close-range opener.

But Kiel skipper Hauke Wahl scored in the 95th minute to force extra time and Bayern, who brought on star striker Robert Lewandowski with 74 minutes played, could not find a third goal as the tie went the distance.

The first 10 penalties were successfully put away but substitute Marc Roca was denied by Ioannis Gelios, setting up Bartels to convert and send the home side through 6-5 on spot-kicks, with Darmstadt to come in the last 16.