Manchester United boss Sir Alex Ferguson has paid tribute to Dimitar Berbatov.

The 31-year-old Bulgaria striker, signed from Tottenham for £30million on transfer deadline day nearly four years ago, is unhappy because he cannot be guaranteed a first-team place at Old Trafford.

Bayern Munich, Borussia Dortmund and his former club, Bayer Leverkusen, are ready to fight for his signature, and Sir Alex said: "Berba is a top, top player who has years left at the highest level."