Monaco - Monaco's Colombian striker Radamel Falcao's requires surgery on the left knee injury he picked up in Wednesday's French Cup tie casting doubt on his participation at the World Cup.
News of the star striker's operation was confirmed on Thursday in a statement issued by his club and will have caused consternation back home in Colombia.
Monaco revealed their record signing had suffered "an anterior cruciate ligament strain" in the 3-0 win at amateur side Chasseley.
It added: "Surgery is required. The doctors will do everything possible to enable Radamel Falcao to recover as quickly as possible."
Falcao faces a lengthy spell on the sidelines, and although the club did not specify how long they expected him to be out of action the news will raise concern back in Colombia who are drawn in Group C at the World Cup with Ivory Coast, Greece and Japan.
On Wednesday, Falcao crumbled to the ground following a challenge and needed lengthy treatment before being carried away on a stretcher just before the interval in his club's victory over Chasseley.
Chasseley disclosed they have received e-mail threats in Spanish, and Soner Ertek, the player whose tackle inadvertently caused the injury, was forced to close his Facebook page after it was targeted with intimidating messages.
Chasseley's club president Jocelyn Fontanel said there had been no malice in Ertek's tackle.
"There was no aggression," he insisted.
"Accidents happen on the pitch. It wasn't violent ...
"It upset me the whole match, especially as I was beside the Monaco directors.
"Soner didn't do it on purpose, we're not a nasty team. Now there are threats on the internet. I don't know whether we should take them seriously.
"I'm very upset for Falcao."
Falcao joined Monaco for €60 million from Atletico Madrid.