Wayne Rooney injury could wreck Dimitar Berbatov exit from Manchester United

Pain game: Manchester United's Wayne Rooney is stretchered off with a leg injury sustained in a clash with Fulham's Hugo Rodallega during the Premier League clash at Old Trafford yesterday (Getty Images)

Manchester United will assess the extent of Wayne Rooney's injury before allowing Dimitar Berbatov to leave for Fiorentina.

The Italian club are confident that a £5m offer for the 31-year-old striker will be accepted, although should Rooney's injury keep him out for longer than the four weeks predicted by his manager, Sir Alex Ferguson, it will hinder the deal.

The gash in the striker's thigh, caused by a collision with Fulham's Hugo Rodallega on Saturday, was so serious that Rooney had to be stitched under general anaesthetic and, if there has been muscle damage, Ferguson's prognosis may have to be doubled.

Nevertheless, after offering Berbatov a two-year package worth £3.2m, Fiorentina are confident that the Bulgarian will leave Old Trafford.

In contrast to Michael Owen, who appeared happy enough with League Cup football, Berbatov does not want to stay at the club if he barely plays.

Even with Rooney on the sidelines, he would still be only United's fourth-choice forward and keeping him to the final year of his contract would cost the club around £4m in wages.