Robert Lewandowski was thought to be on his way to Manchester United in the summer, however, there might be a spanner in the works, with German giants Bayern Munich reportedly moving up the queue for the Borussia Dortmund frontman.

Lewandowski is widely tipped to leave Dortmund at the end of the season, with his contract set to expire in 2014, and a new deal not agreed upon.

Old Trafford was thought to be Lewandowski's destination, with United reportedly agreeing personal terms as well as a tentative transfer fee with Dortmund. Lewandowski had also previously stated his admiration for the Premier League and his desire to play in England in the future.

However, if a report by Italian site TuttoMercato is to be believed, Bayern are now the favorites to seal the coveted Poland international's signature, with the 24-year-old already agreeing to join the German giants.

Pep Guardiola is set to take over at Bayern next season, and the Spaniard has already identified a few targets, which also include Liverpool striker Luis Suarez.

Lewandowski has been one of the most consistent strikers in the Bundesliga over the past few years and was instrumental in Dortmund winning back-to-back titles.

While Bayern already have a prolific striker in Mario Gomez, with Mario Mandzukic also impressing, adding a player of Lewandowski's caliber will make Bayern, who are well on their way to the Bundesliga title, into an even more formidable team.

It is unlikely that Dortmund will allow one of their best players join their biggest rivals; but if Bayern were to make a big offer for a player who will only have one year remaining on his contract come the end of the season, the German champions might not have much of a choice other than to agree to sell.

United are still thought to be interested, but Sir Alex Ferguson will not only need to match Bayern's terms, but also find a way to offload one of Danny Welbeck or Javier Hernandez, with Wayne Rooney and Robin Van Persie unlikely to be let go.