Reading manager Steve Coppell fears Ivar Ingimarsson will be sidelined 'for some time' after undergoing knee surgery.
The Icelandic defender has been playing through the pain barrier over recent months, but was forced out of last week's meeting with Wolves.
Coppell insists the operation did not involve major surgery, but does not expect Ingimarsson to return to action any time soon.
"He has had the operation now and he will be some time," Coppell told the club's official website.
"We do not know how long exactly, he has had a little repair but it is not major."