Giuseppe Rossi is doubtful for Italy\'s UEFA EURO 2012 qualifier against Serbia on Friday because of a knee injury. The Villarreal striker ended yesterday\'s training session with a left knee problem that has troubled him in recent weeks. \"He has suffered the same type of problem that he had in Spain,\" Italy team doctor Enrico Castellacci told Gazzetta dello Sport. \"He has a knee hyper-extension. He will remain with us and we will evaluate if he can recover in time for Friday\'s game.\" Rossi becomes the latest injury concern for Italy coach Cesare Prandelli. Inter Milan forward Giampaolo Pazzini is set to miss the game in Belgrade with a foot injury, while Palermo defender Federico Balzaretti is also doubtful with a muscular problem. Zenit St. Petersburg left-back Domenico Criscito left Italy\'s training camp yesterday with a back injury. Italy have already secured a spot at EURO 2012 and remain unbeaten in qualifying.