Cristiano Ronaldo remained on the bench throughout Manchester United's heavy defeat to Manchester City, something which club legend Roy Keane believes shows a lack of respect.

Even though Anthony Martial, who was chosen to come off the bench and spark a revival by Erik ten Hag, scored twice, Keane still feels Ronaldo should've been given an outing.

"I think it's ridiculous for a player of his stature, for Man United to just keep him [on the bench]," Keane said on Sky Sports.

"Even today, could he have brought him on? Of course, he could've brought him on. So what if you're 4-0 down? If you look at his goal scoring record, he has as good a chance as anyone of putting the ball in the back of the net.

"People obsessed with the pressing side of the game. If you put the ball in the right areas, he'll score goals."

He then went on to state how it was disrespectful, even though the Portuguese was trying to force his way out of the club in the summer.

"Man United are showing disrespect to Ronaldo. I think he should've been let go before the transfer window [closed]," he said.

"He's one of the greatest players ever, he had options, this idea that he had no options is rubbish. He did have options, four or five very good options.

"Okay, today, the manager brought [Anthony] Martial on, who scored two, so yeah that's justified. But generally speaking, the bigger picture, he's not going to play Ronaldo, we know that.

"He's played in one or two European games, it's just going to get uglier as the season goes on.

"Okay, Ronaldo's motivated with the World Cup coming up. But if he's sitting on the bench for Man United week in week out, it's not good."