Callum McGregor has acknowledged that St Mirren offer very recent evidence of what can happen to Celtic if standards drop.
The Buddies' 2-1 win at Parkhead in the Scottish Premiership on January 30 was their first win in the east end of Glasgow since April 1990 and brought more criticism on already under-fire manager Neil Lennon and his players.
The reigning champions responded with back-to-back wins for the first time this year against Kilmarnock and Motherwell albeit they sit 21 points behind leaders Rangers with two games in hand.
Ahead of the return fixture against St Mirren on Wednesday night, stand-in skipper McGregor outlined the pressures the Hoops are always under.
The Scotland midfielder said "You are expected to win every game at Celtic, no matter what, no matter who the opponent is, and when you lose it is always a sort of shock result.
"Like the manager said, the performance wasn't good enough, we know that.
"Everyone was below par and it just shows you that's what can happen if you don't perform well on the day.
"In seasons gone past, that's why we have been so good and so consistent, you go into every game knowing you have to perform.
"So it just showed again that if you come off it or lose focus or you are not quite right on the day that you can get beat and it is always a bad result when you lose a game at Celtic and we totally deserved it.
"The two wins have been good to try and build a bit of momentum but it is important for us to stay calm and keep working, keep trying to do the right things that have got us the results."
