UEFA Champions League: Barcelona eye victory against Bayern Munich

Barcelona's Brazilian forward Raphinha (L) fights for the ball with Bayern Munich's Canadian midfielder Alphonso Davies during the UEFA Champions League two years ago. [AFP]

Hansi Flick has rapidly moulded a ragged Barcelona into a potent threat to Europe's elite and the visit of his former Bayern Munich side in the Champions League on Wednesday is their first acid test.

The Catalans have not reached the semi-finals of the competition since 2019 and were humiliatingly thrashed 8-2 by the German giants in 2020, when Flick was at the helm in Bavaria.

Five-time Champions League winners Barcelona lifted the trophy most recently in 2015 and failing to thrive on the road to this season's Munich final would mark a decade in the doldrums since.

Flick's Barcelona have started La Liga in stunning fashion with nine victories and just one defeat in 10 matches, while scoring 33 goals.

The league leaders delivered a stylish display of attacking football to rack up a 5-1 win over Sevilla on Sunday ahead of the Bayern Munich clash and Saturday's La Liga Clasico battle against Real Madrid.

Barcelona thrashed Young Boys 5-0 earlier in October in the Champions League after an opening 2-1 defeat at Monaco.

Flick, who led Bayern to a sextuple in 2020, has swiftly transformed a Barcelona side who won nothing last season under Xavi Hernandez into a swashbuckling force despite injuries to several key players.

Gavi made his comeback from a severe knee injury on Sunday, while Frenkie de Jong, Ronald Araujo, Andreas Christensen, Marc-Andre ter Stegen and others face long spells on the sidelines or are only just returning.

Perhaps the most crucial difference has been former Bayern striker Robert Lewandowski's return to form.

Flick has backed the Polish striker to the hilt despite his struggles last season and the 36-year-old has responded with 14 goals in 12 matches across all competitions.

"Robert is an absolute professional, working hard on his fitness -- this body he has, it's not this age," said Flick earlier in the campaign.

"(Scoring) is his job and he is doing this great over years now, not only this year... this is a goal-getter, a striker who scores goals."

Flick has given Raphinha and Lamine Yamal freedom to roam in attack and pushed the team as a whole up the pitch, allowing Lewandowski to spend more time in the area.

The forward is getting more chances than he did for swathes of last season and with his confidence high, he is finishing them off.

However Flick said his and Lewandowski's Bayern reunion would not just be a battle between the striker and Bayern hitman Harry Kane.

"It's never a battle about players, it's a battle about the (whole) team," said Flick on Sunday.

Meanwhile, RB Leipzig host Liverpool in the Champions League today as Jurgen Klopp's recent past and not-too-distant future collide.

The 57-year-old will not be there at the Red Bull Arena, but his shadow still looms over the contest.

Klopp stepped down as Liverpool manager in the summer citing exhaustion after a successful nine-year spell which included lifting the Champions League and Premier League.

In October, Klopp announced his return to football, not as a coach but running Red Bull's football operations, which oversees clubs in several cities including Leipzig, Salzburg and New York.

He will be absent from the game, choosing to wait to attend a match after starting the role in January.

While the appointment was a surprise in Germany and in England, the focus on Leipzig has been particularly acute.

In a strange quirk of the fixture list, Leipzig's five fixtures after the announcement includes games against each of Klopp's former clubs: Mainz, Liverpool and Borussia Dortmund.