Motherwell boss Stephen Robinson has "massive concerns" over a Fir Park bug which leaves five players in doubt for Saturday's Ladbrokes Premiership clash with Hearts.
Defender Peter Hartley missed the midweek win at St Mirren with an illness and others are facing a race to be fit for the visit of the Jambos.
Robinson was keeping names close to his chest but said: "There is a bug going about and people with high temperatures so we've sent a few home.
"I won't give specific names or too much away but four or five boys have been sent home in various stages of this week so we are just going to have to assess it on Saturday morning.
"We are aware how infectious it is for 48 hours, so the doctor has advised people to stay away from the ground at the moment.
"Same bug that Peter had. It's a massive concern, you don't know who is going to come out with it next.
"We are in a closed environment. It seems to be quite contagious.
"Over the last few weeks we've had four or five different people with it and some have managed to play. Some have high temperatures as well. It seems to be two different things.
"We won't name the team, we will just see how they are tomorrow. We won't be decimated, put it like that.
"It might be one or two that will be impacted but we will still have a strong side."
While the Steelmen are one point behind third-placed Aberdeen, Hearts are ninth and have won one out of their last nine league games.
After the 1-1 draw with Livingston on Wednesday Austin MacPhee, who has won one of five games as caretaker manager, admitted he expects German manager Daniel Stendel to be confirmed as the club's new boss at the start of next week.
Asked if he had sympathy with MacPhee's situation, Robinson said: "I have sympathy for absolutely every manager in the game.
"It's a very difficult job. You are under constant pressure and it takes over your life.
"I know Austin as well. I'm sure he will do his very best and has done in difficult circumstances.
"They've got players that can hurt you, if they are at the top of their game.
"So we are taking nothing for granted. We must turn up. You can't turn up and just expect to beat teams because of league positions.
"There is nothing in this league at all. We will not take anything for granted, we will make sure we are on the top of our game."