Dimitar Berbatov's representatives have confirmed they have spoken to Bayer Leverkusen about the possibility of the striker returning to the Bundesliga club, saying that such reports are "more than just a rumour".

Berbatov has been on the fringes of the Manchester United side this season, starting only two Premier League games, but provided a timely reminder of his talent with a hat-trick in the 5-0 Boxing Day win over Wigan Athletic. The Bulgarian's contract ends next summer and if United decide not to exercise their option of a 12-month extension, he would be able to talk to other clubs at the start of January about a free transfer.

Berbatov spent five seasons at Leverkusen before moving to the Premier League with Tottenham Hotspur in 2006 and he appears receptive to a return to Germany, should he not stay at Old Trafford.

"Leverkusen have it on their minds to get Berbatov," Ivan Dobrinov, a member of the group which represents Berbatov, told the German newspaper Bild. "There is contact, but nothing concrete yet. It all depends on United's plans. We wait until 2 January.

"Until then, United have the option but if that does not happen then Berbatov would be a free transfer in the summer. The player has never forgotten Leverkusen, the club is still very dear to him. Furthermore, he has a good relationship with the leadership at Bayer."

The Leverkusen chief executive, Wolfgang Holzhauser, also confirmed tentative talks have taken place but accepted the 30-year-old could remain at United.

"I would even say that the contact is friendly," Holzhauser said. "But there is certainly nothing concrete at the moment. I also read that Manchester United would like to extend his contract."