Head Coach Martin Jol revealed this afternoon that the Irish striker has been carrying a knee problem for the last couple of weeks.
It's a headache for Martin with top scorer Jermain Defoe suspended and he will lave any decision until the last minute.
"Robbie Keane has a problem with his knee," said Martin. "We'll look again at the situation tomorrow but it doesn't look very good.
"He's alright, a good character and he's played on but it's swollen up a bit. If the swelling has gone down, it's no problem, if it hasn't we might have a problem.
"He had treatment this afternoon, more tomorrow and then we will make a decision."
Robbie Keane is a doubt for Saturday's Barclays Premiership clash against Manchester City.