Stoke City say on-loan Liverpool winger Oussama Assaidi will miss a "number of weeks" with a knee injury.
The Morocco international, 25, suffered ligament damage during the club's recent training camp in Dubai.
Assaidi has scored four times in 22 games for the Potters this term, having made only 12 appearances for Liverpool last season.
"He got a block tackle in training and just opened up his knee ligaments," boss Mark Hughes told the club website.
"He is going to be out of action for a little while. We obviously hope that he is going to be back sooner rather than later, but it is one that we will just have to wait on unfortunately."
A statement on Stoke's website added that, while Hughes would not put a timescale on Assaidi's absence, "he will be absent for at least a number of weeks".
Meanwhile, defender Robert Huth returned to full training in Dubai after undergoing knee surgery earlier this season.
"We are trying to push him on a bit further now because we have had to take our time with him after having a few initial set-backs," Hughes added.
"He is starting to cope with the work we are asking him to do which is encouraging, and hopefully we can step him up again now."