Struggling Vasilis Barkas is one of the key reasons Celtic have fallen behind in the title race because he 'doesn't make saves', claims Michael Stewart.
Fingers were again pointed at £5million stopper as he failed to stop Callum McGregor 's deflected header sailing into his own net in the 1-0 derby day defeat.
The Greek cap has failed to hold a regular starting spot since the big-money summer move from AEK with Scott Bain and Conor Hazard given the place between the sticks by Neil Lennon.
With his opposite number for Rangers Allan McGregor earning rave reviews for decisive saves and comparisons to Ibrox legend Andy Goram, Stewart believes the tale of two keepers sums up the differences between the Scottish Premiership top two.
When asked about the performance of veteran keeper McGregor on BBC Sportsound, Stewart said: "He was absolutely top drawer, Allan McGregor is a top class keeper.
"That's another stark contrast between the sides. Celtic have been scrambling around to see who their number one goalkeeper is.
"They've signed Barkas for almost £5million and he has simply not been good enough.
"He doesn't make saves, he's not an imposing character and he doesn't breed confidence in the side, and that has permeated throughout the side.
"It's been one of the sources of the problems they have had defensively. They've got a goalkeeper who isn't commanding and doesn't breed confidence.
"Rangers on the other hand, you look at Allan McGregor, he's absolutely top drawer. He keeps Rangers in the game.
"If Edouard's first one goes in, but he saves it and he's offside on the second one but he doesn't know that and he jumps right back up and makes the save. The one from Griffiths that he deflects onto the post.
"Allan McGregor makes saves that make a difference to the game."
