Kilmarnock could be without Borja Perez for their SPL clash with St Mirren on Saturday.
The Spanish midfielder has suffered an abductor muscle strain and is doubtful for the Rugby Park clash.
Assistant manager Jimmy Nicholl said: "We came in this morning and Borja was on the treatment table.
"Alex MacQueen [the Kilmarnock physio] will look at him in the morning and find out if it's going to rule him out for the weekend.
"But the way he's looking at the minute it looks as though he could be out."
Gary Harkins could come back into the starting line-up after a head knock as Killie look to hone their attacking game amid the continuing absence of Paul Heffernan, who is recovering from a broken collarbone.
Former Celtic striker Cillian Sheridan made his debut in the 2-1 defeat by Hibernian last weekend and Nicholl has high hopes for the Irishman.
He said: "I'm really optimistic. Sometimes when you get a player in you feel it's going to make a difference, and I just feel it's going to make a difference to the team and our chances of winning games.
"Eventually once he gets settled in, because of the way he is and his physique, we don't really have anyone like that, he will really help the other strikers.
"We've got loads of strikers, we just have to get the right blend.
"With Cillian we might have to change the style and play two strikers, at the minute we're playing one."
- Cillian Sheridan joins Kilmarnock on two-year deal after leaving CSKA Sofia
- One-year Kilmarnock deal for former Real Madrid youngster Borja Perez