Neil Lennon admits that his defence is struggling for confidence after Ireland defender Shane Duffy came in for some heavy criticism over recent displays in the Bhoys side.
Celtic have conceded eight goals in their last three games, most recently a 3-3 draw with Aberdeen as Rangers have profited to go six points clear of their Old Firm rivals.
Duffy was apportioned blame for at least one of the goals against the Dons and while boss Lennon didn't single out the Derry native, he said after the 3-3 draw that "we're a little bit fragile with the confidence at the minute".
Lennon added: "The goals are really poor from our point of view. We need to be a lot more defensive-minded and a lot more solid".
But former Celtic player Kris Commons didn't hold back in his criticism of the Derry native who is on loan from Brighton.
"Duffy just looks like an accident waiting to happen, a bomb scare," Commons said.
"He's been rank rotten from the minute he walked through the door. He's a proven operator in the English Premier League. At 28 years old, there's still a chance that he might come good eventually. But he needs to get himself up to speed and sharpish. With so much riding on this season, Celtic can't afford to be carrying any passengers."
Lennon has stood by Duffy despite those testing times, pointing out that the player had been unable to settle in as well as he'd have liked due to the disruption of international and also an illness.
"As the season unfurls and goes along, he'll play a huge part for us. Shane's a good type and he will revel in it eventually. But he's only just in the door. He's been thrown in without any real pre-season. He'll get better and better - and he'll be a stalwart for the team," Lennon said.
"Shane didn't play any football for nine months. All of a sudden, he's played 14 games in about five weeks. He played three games for Ireland, then had an abscess in his mouth that was giving him a lot of pain. He flew back into Glasgow and had some emergency dental work. Then we had to roll him out against Rangers."
Celtic are away to Lille in the Europa League on Thursday.