Swansea City coach Alan Curtis says Michu could be sidelined for at least six weeks and as much as three months if he undergoes surgery.
The Spaniard has been struggling with ankle and knee injuries and could be forced to have an operation with the Welsh club to make a decision on Tuesday.
Curtis said that Michu, whose ankle issue has flared up again, may go under the knife in order to address the problem area for good.
"They will decide when the operation will be, if an operation is required. It probably will be," he told reporters.
"Hopefully we're looking at something maybe around the six-week mark [out].
"It will be a blow obviously to lose him for that length of time, but possibly we were looking at two to three months.
"But to be fair to him it's something that needed to happen, because he's been struggling with his knees and his ankles.
"It's interrupted his training and he's missed a fair chunk of game-time this year."
