Former Premier League referee Dermot Gallagher insists Bobby Madden was right to send off Nir Bitton for his last man challenge on Alfredo Morelos - and Shane Duffy was lucky not to see red, too.

Bitton was given his marching orders in the second-half of Celtic's 1-0 defeat to Rangers despite teammate Kris Ajer claiming he was covering.

Madden was quick to brandish the card, and Gallagher reckons he was right to do so. "I watched this game live and I thought he’d get sent off," Gallagher told Sky Sports. "Once Morelos is past, he’ll go straight towards goal and the law says ‘Has he a goalscoring opportunity?’.

"That means can he get a shot away at goal, and I would suggest he would get a shot away at goal long before Ajer gets across because he’s parallel and there’s a great distance between them.

"It’s a challenge Bitton doesn’t need to make. Once you make a challenge like that you know it’s going to be a red card. I sometimes think a player should let him go and take a chance on the goalkeeper making a save or the player missing.

"For me, it’s a red card."

Gallagher also addressed Duffy's lunge on Ryan Kent that resulted in a yellow card. And he claims the Irishman could have been red carded on another day. "This is as high a tariff yellow card as you get," he said. 

"It must be bordering on red, not so much for the first leg but the fact he follows through. The ref has seen that, he’s just sent off Bitton, he needs to be assured that it really is pushed over the boundary but as it was right on it, he gave Shane Duffy the benefit of the doubt. As I said earlier, another day another referee that could have been a red card."