Everton boss David Moyes had revealed Steven Pienaar could face up to a month on the sidelines with a groin injury.
Moyes, speaking after Everton's win over Birmingham, said the South African picked up the injury during training on Wednesday.
"He hurt his groin on Wednesday in training and it looks as if he might be out for two to four weeks," Moyes told Sky Sports.
"Two weeks would be good, four would not be. It is a real blow because he played so well at Fulham and is an influential player. I'm hoping he can heal quickly and at least we have got the international break coming up."
The Scot also raised concerns about goalscorer Tim Cahill's fitness, claiming the Australian was close to missing the clash at St Andrews.
"There was a doubt about Cahill today. He is still not looking 100%. He has not trained enough for me to think everything is absolutely right."