Kevin Strootman underwent surgery on Friday and cartilaginous damage was discovered during the procedure.
Roma midfielder Kevin Strootman has revealed he will be sidelined longer than expected after undergoing knee surgery on Friday.
The Netherlands international on Thursday allayed fears that he is set for another long absence after suffering a setback in Sunday's 1-1 draw with Fiorentina.
That was only the 24-year-old's sixth Serie A appearance since returning from an anterior cruciate ligament injury, which he sustained in March last year.
Strootman has now stated that further damage was discovered during his operation.
He tweeted: "The scar tissue from my previous operation has been removed successfully today. Unfortunately some cartilaginous damage, caused by the knock in the Fiorentina match, was found too.
"This means I have to take a longer rest period than anticipated earlier and I am extremely disappointed that it will take much longer before I can be back on the pitch again."