Michael, who missed his first game of the season last Saturday because of a slight hamstring problem, would not be risked if there was a possibility of him sustaining further damage.
However, with Fredi Kanoute, Paolo Di Canio, and Nigel Winterburn, who all have similar problems which ruled them out last weekend, there is a worry that if they played they could put themselves out for weeks.
Explains physio John Green: "We sat down with Glenn and discussed the risk factors with certain players, and it was deemed inappropriate for Paolo, Nigel, and Michael to play last week.
"They don't really have tears of any description, it is just a case of players saying they feel tight and that is usually a precursor to a tear.
"If there was a tear of a significant nature it could rule them out for four to six weeks so it is a case of missing one game to hopefully play nine or 10 games in the next five weeks.
"Fredi's injury is a little more severe because of the nature of the way he plays the game and he has a proper tear.
"Paolo and Nigel should be back for the game against Aston Villa on Wednesday, and Fredi at Manchester United next week as the rehab that we have put them through isn't complete yet.
"Muscles are more vulnerable when they are tired so it was sensible from the management to pull them out, although it was a hard thing to do.
"Michael will play this weekend; with him we are just dealing with some stiffness.
"It is a case of the long term being more important; we have played about 13 games so far and we have nine in five weeks so the games are becoming closely knit."
John was delighted to see Joe Cole return for his first full game since September 15 at the weekend and adds: "Joe is back and there are no residual problems - just as we anticipated; it is a case of getting sharper and sharper in training but with the period of heavy fixtures we have it would be prudent to be cautious."
As for the injury to Steve Lomas sustained at the weekend, John adds: "Steve Lomas has fractured the fourth toe after Steffen Freund rather clumsily stepped on his foot; it is a disaster for Steve and the club and means he won't be back until the end of January.
"I think the real disappointment was added to when you saw how well he played against Tottenham; his fitness was good and I felt he was missed in the second half."
As for other players, John says: "Gary Charles is training and it is a case of establishing himself in the reserve games and emulating Paul Kitson's return.
"Titi Camara is training; there has been no treatment on his knees for a while but he requires further improvement in his overall fitness before he could be considered for a place in the reserves, and subsequently the first team."