Manchester United legend Peter Schmeichel attributed the defeat on Erik ten Hag’s decision to replace Kobbie Mainoo at halftime.

The teenage midfielder’s progress over the previous month has been one of the few bright spots in a dismal season for the Red Devils thus far.

Mainoo did a fine job of disrupting the home midfield during a lethargic first 45 minutes at the City Ground, so his replacement by Scott McTominay at halfway came as a surprise.

However, the Scotland international, who has been one of the club’s standout performers this season, did not fare well in defensive midfield for either of Forest’s goals in their rout.

In an interview with Premier League Productions following the game, Schmeichel blasted United’s choice to sit Mainoo.

“He makes a substitution, and I think that has a really big effect on the game,” Schmeichel, a former Manchester United goalkeeper, said.

“As I previously stated, I understand why you want McTominay on, but not for the guy you take off.”

“The guy you take off Mainoo is a great player, and he played well.” He had perfect control of that section of the pitch.

“There was no need to make that change when you have other players on the field doing nothing for you.” I’m intrigued by the substitution and its implications for the rest of the team.

“What motivates you to make a change at halftime?” Is this so you can take three breaks instead of two in the second half? Is that it?

“Or is it to make an impression?” If you want to have an impact, you must keep impact players on the field. That had a big impact on the game.”

Ten Hag is accused of taking the easy route

Stuart Pearce, a woodland legend, concurred with Schmeichel but accused Ten Hag of choosing the easy route.

“Sometimes as a manager, you go in at half-time and you feel you have to make a change to make an impact and get a mentality turnaround in many ways,” he said.

“It sends a bad message when you make a substitution and take a young kid off who I didn’t think was doing badly for me.”

“He’s the one bright thing but it sends a message out that I’ve took the easy way out, that’s how I see it.”

Mainoo will almost certainly have another chance to show off his skills when United go to Wigan in the FA Cup third round on January 8.