Manchester City midfielder Michael Johnson is facing a spell on the sidelines after suffering a groin injury in last night's 1-0 defeat of Sunderland.
"Michael just could not run anymore," he said.
"We will make a decision on an operation tomorrow but with an international break coming up, now would be a good time to have it.
"I am not sure how long he would be out but it won't be a long time, maybe two or three weeks."
Eriksson also confirmed Nedum Onuoha will be sidelined for around 10 days with a groin problem, while Micah Richards should be available to play against Portsmouth on Sunday.