Michael Stewart reckons Alfredo Morelos is "undermining" Rangers' progress as the striker was embroiled in a flashpoint with Mark Connolly.
The Colombian caught the Dundee United man in the face in a first half incident at Tannadice, but only received a yellow card for the foul.
Morelos has only scored seven goals in 22 games this season and Stewart reckons the striker lashed out because he is frustrated with his recent scoring woes.
And the pundit believes Morelos could have easily cost Rangers three points on Sunday and these type of incidents are diminishing all the good work Steven Gerrard's side are doing at the moment.
He said on Sportscene: "He's not the player he was a year ago.
"Before he would be on his toes, the ball would drop to him and he'd smash it into the back of the net.
"You can see the frustration oozing out of him.
"As a striker you go through spells where you can't score but the problem, I think, with Morelos and for Rangers as a whole he's not the talisman that he was a year ago.
"I think Rangers as a team could comfortably have him out of the side and Roofe could play at the top. Aribo could come into the side in the area that Roofe is playing in.
"I think the team would actually improve. Morelos, he doesn't show anything as a team player.
"Before he was such a goalscorer and a real threat. He isn't the same.
"When he's coming up with those incidents like we saw with his forearm that's really undermining all the good work that Rangers are doing at the moment. He's not the player he was a year ago."
Former Celtic defender Gary Caldwell also condemned the incident, but insists it was more of a "forearm smash" than an elbow.
He added: "I don't see an elbow either - but I see a forearm smash in the face.
"There's intent because he's looking at him.
"What I can't understand is the referee books him so he's seen something. How he can't, along with his linesman, come to the right decision there I think is poor."
