Madrid - Spanish Liga club Villarreal announced on Friday that Nihat Kahveci will be out of action for between four and six weeks. Nihat, 28, tore the muscles in his right calf in last Saturday's 1-0 win away to Sporting Gijon, a win which leaves Villarreal joint top of La Liga with Valencia.
It is a similar injury to the one he suffered at Euro 2008 playing for Turkey, and which kept him out of action until two weeks ago.
Juan Albors, head of Villarreal's medical services, hinted on Friday that Nihat might need an operation.
"Because of the complexity of the area of the injury," he said, "if progress is not what we desire, then we cannot rule out other options ... But let us see how he evolves."
Because of the injury sustained in Gijon, Nihat missed Tuesday's 1-0 home win over Glasgow Celtic, which keeps Villarreal joint top of Champions League Group E with holders Manchester United.