Whatever happened in the dressing room - I don't know, but I'm a great believer that you need to play your best players and for Gordon not to play Aiden McGeady- there's something wrong."
He continued: "You've got to back the manager; it's an unwritten law that you don't have a go at the manager in the dressing room, no matter if you're right or wrong.
"I did it quite a few times and got fined - every week actually. When I was at Celtic, Billy [McNeil] fined me every week, not because I answered back but he knew on a Saturday he could play me no matter what problems I had with the club because they owed me money and all that sort of stuff.
"But whatever the problems with us, when I crossed that line on a Saturday he knew I would give 100 percent, so there is something wrong that he [Strachan] can't trust Aiden to do that because he is a quality player, there's no doubt about it."
"They will miss him and when Aiden McGeady is on form he is one of the best players in Scotland."
Celtic have a depleted squad for the huge match and McAvennie is hoping Strachan has disciplined McGeady for the right reasons.
He explained: "It might be the making of him but you need to back the manager.
"I know Gordon and I hope he wouldn't do it just for spite. Aiden's obviously in the wrong."
Yours in Celtic
Clydebuilt