Former Celtic striker Chris Sutton has told The Scottish Sun that Jozo Simunovic must start for the Bhoys against Molde - and he doesn't understand why the club signed Tyler Blackett.
Celtic have endured a winless start to their Europa League campaign this season, with two 2-2 draws against Ajax and Fenerbahce and a 3-1 defeat away at Molde.
That loss in Norway piled the pressure on manager Deila, and he now desperately needs a win against Ole Gunnar Solskjaer's side tomorrow evening.
A 3-1 win over Aberdeen on Saturday has Celtic in good form, but former Bhoys striker Chris Sutton still has some concerns about the defence.
Sutton has told The Scottish Sun that 21-year-old centre back Jozo Simunovic must start, even though he faces a late fitness test ahead of the game, whilst he has also been impressed with the performances of teenage left back Kieran Tierney.
Sutton also added that he can't understand why Celtic even signed Manchester United defender Tyler Blackett this summer, given that Deila has barely used him, and admitted his doubts over Nigerian international centre back Efe Ambrose.
"I thought Kieran Tierney did well against Fenerbahce and I was surprised that he didn’t start in Molde," said Sutton. "I think Jozo Simunovic has to play in this game. He’ll pick Dedryck Boyata and Mikael Lustig. That’s what the back four will be."
"But there are things that I don’t understand, like the signing of Tyler Blackett and the fact he hasn’t played. In fairness to Ronny, he watches training and sees all the players. He doesn’t pick a team to go out and lose. I just think that when certain players such as Ambrose play, and you are trying to play out from the back, we all know what is going to happen," he added.
If Simunovic misses out, Deila will pick between Ambrose or Blackett to replace him - and it seems that both players have something to prove to ex-Bhoys star Sutton.