Martins returned to action, following a long spell out, in the Carling Cup defeat to Tottenham, but on Thursday he duffered a severe reaction.
Martins told The Sun: “My right knee is very swollen, so much so that I can’t contemplate how long I will be out for.
“The swelling only started on Thursday morning. I didn’t feel anything after the game. I just woke up and saw how terrible and bad it looked.
“I have been told by the doctors here that I could be out for another six weeks, but when they said ‘could’ — you know it’s bad.”
