Celtic will appeal against the red card shown to Dedryck Boyata in the draw at Hamilton Academical despite manager Ronny Deila having criticised the defender.
After Friday's game at New Douglas Park, the Norwegian had said he agreed with referee Craig Thomson's decision.
But Deila has changed his mind after reviewing television footage.
"I have seen it many times and, when you've seen it from all angles, it's the wrong decision," Deila said.
Deila reiterated his opinion that the Belgian defender could have avoided the red card by staying on his feet rather than lunging into the tackle on Hamilton's Carlton Morris.
"I'm still saying that in this situation I want my player staying on his feet, because we have quick defenders and running with people is better than taking chances and putting the referee in a bad situation.
"He makes his decision and hits the ball, in my opinion it's not a red card."
Deila has been criticised for his post-match comments and not defending his player, but he remains adamant that "it's important to be honest" in his assessments.
"I will never say anything about a player personally, but this is a decision on the pitch," Deila said. "I don't see any problem with that.
"I'm honest with the players. This is not an attack [on Dedryk]. Someone who has and will defend his players is me.
"I have no regret with what I did in that matter. But I was wrong because it was in my opinion no penalty."
Celtic remain in contract talks with the Australian midfielder Tom Rogic, with Deila insisting that the player remain in his long-term plans for the club. "We're working to get that renewed," the Celtic manager said.
With Dundee visiting Celtic Park on Wednesday, Deila said that his team would have to be strong defensively to cope with the attackers in Paul Hartley's side. The Celtic manager has yet to name his squad for the game, but he added that there is no arrangement with Manchester City over Patrick Roberts starting first-team matches during his loan spell at the club.
"The agreement is that he comes to us and we try everything we can to develop him as well as possible," Deila said.
"If he's good enough for the team then he plays and if he's not then he's on the bench. You can't make promises, he's a young player and we're happy to have him for one and a half years."
Deila also confirmed that he will speak to Leigh Griffiths about continuing to be the nominated penalty taker after his miss against Hamilton, but he retains the manager's confidence.
"I'm not afraid to give that chance to Leigh, he knows where the goals are standing," Deila said.