Sean Davis has suffered a blow to his Bolton comeback and could be out of action for up to two months.
The midfielder missed virtually the whole of last season after undergoing surgery to repair an articular cartilage injury.
As he seeks to return to first-team action, he came out of a recent reserve game against Manchester City feeling some discomfort in his knee.
Bolton boss Owen Coyle has now vowed to take no risks with his recovery as the 30-year-old aims to make the first team for the first time since last August.
Coyle said: "Sean played for the reserves the other week against Manchester City and he felt a little twinge in his knee.
"We've done a scan and he has been told to rest completely for six to eight weeks.
"It's disappointing for Sean and the football club because he has worked ever so hard to get himself in decent shape but we have to make sure that we do the right thing.
"It's the advice that we have been given and that's where we are with everything."