Colombian national team and AS Monaco striker Radamel Falcao underwent successful surgery Saturday in Portugal to repair the torn anterior cruciate ligament in his left knee and now will race against the clock to recover in time for the World Cup, which gets underway on June 12.

The operation "went well," Portuguese surgeon Jose Carlos Noronha said, although he stressed that the 27-year-old star faces an uphill battle in trying to get back on the field for an official match in less than five months.

"I still have faith he can be in the World Cup, although my faith is guarded ... We'll have to see because it's going to depend on several things," the world-renowned ACL expert told reporters at the Hospital da Trindade in Porto.

Falcao, who played for Portuguese club F.C. Porto from 2009 to 2011 before moving to Atletico Madrid and later to his current club, French-league side AS Monaco, is scheduled to be released from the hospital on Monday.

He will then undergo rehabilitation under Noronha's supervision in Portugal for several weeks before going back to Monaco and continuing his rehab there.

"I'm going to exaggerate a little, but I think he'll have a 50 percent chance of going to Brazil. We have to go step-by-step and three and a half months from now we'll be able to say something with more certainty," Noronha said.

The typical recovery time from serious knee injuries like the one Falcao sustained is six months and the World Cup is less than five months away.

The star forward was injured during a French Cup match Wednesday against fourth-division side Monts d'Or Azergues Foot that Monaco won 3-0. Falcao scored a goal early in the game.

The Colombian international sustained the injury when he was tripped up from behind by defender Soner Ertek, and he was visibly in pain while being carried off the field on a stretcher.

Colombia, which qualified for soccer's biggest showcase for the first time since 1998 thanks in part to Falcao's play, is in Group C along with Greece, Japan and the Ivory Coast.

The Colombian striker also has played a big role in Monaco's success this season. The club is currently in second place in the French league behind Paris Saint-Germain.

Falcao said in a message to his fans this week on AS Monaco's Web site that he is still holding out hope that he can recover in time to play for his country in Brazil.

"I do not conceal from you, my sadness is immense, my heart is broken, but some hope is enough to believe that my dream to participate in the World Cup is still alive. God makes possible the improbable and I believe in him." EFE