Stoke City are waiting on scans to discover the extent of a knee injury suffered by striker Mamady Sidibe.
The Mali international had only just returned to full-fitness before twisting his knee in the warm-up before a reserve team game against Aston Villa on Monday night.
"Mama's twisted his knee. He went over and was in a lot of pain," reserve team manager Mark O'Connor told The Sentinel.
"I don't think anybody touched him, he just went over. I saw him after and he seemed a little better in himself, but once we get him looked at we'll know more.
"It could be that this is just a scare and he's fine by the end of the week. I honestly don't know, but I'm just hoping he's all right."
Sidibe has scored four goals in 24 appearances in all competitions for the Potters this season.