Manchester United winger Bebe could be sidelined for up to six months after tearing his anterior cruciate ligament while playing for Portugal Under-21s in Slovakia on Tuesday night.
The 21-year-old joined United from Vitoria de Guimaraes for £7.4m in 2010, but has played only seven first-team games for the Premier League champions. He was recommended to Sir Alex Ferguson by his former assistant, Portugal national-team coach Carlos Queiroz.
In June, United agreed a one-season loan deal for the player with Besiktas. The Turkish club have contacted United to discuss where his operation should take place.