Italy striker Giuseppe Rossi has suffered ligament damage to his troublesome right knee but not a rupture of the cruciate as feared, his Serie A club Fiorentina announced on Monday.

Rossi's World Cup hopes had been thrown into turmoil on Sunday as he limped off the pitch in the 71st minute following a foul by Liandro Rinaudo in a 1-0 win over Livorno.

The 26-year-old suffered a "second degree injury of the right anterior ligament," his team confirmed after he underwent tests on Monday.

However Rossi's agent, Federico Pastorello, posted a message on Twitter which suggested the striker could return to action within two months.

"It looks like a sprain with damage to the collateral ligament...," Pastorello said. "In six or seven weeks he could be back on the pitch."

Rossi only returned to action this season following a lengthy lay-off because of injuries to the same knee but has hit 14 goals to become Serie A's top scorer and is firmly in the World Cup plans of Italy coach Cesare Prandelli.

Rossi will now travel to Vail, Colorado to be examined by Professor Richard Steadman, the surgeon who operated on him before.

Fiorentina had feared the worst for Rossi, who suffered separate injuries to the same right knee in October 2011 and April 2012, and who has undergone several knee operations in recent years.

The injuries cost him 23 months away between November 2011 and October 2013 and deprived him from playing at Euro 2012 where Italy were beaten by Spain in the final.