Manchester United boss Solskjaer failed to steer his side past Wolves on Saturday, with Raul Jimenez and Diogo Jota on target for the home side.
It was a second consecutive defeat for the Red Devils, who had previously been beaten 2-0 by Arsenal in a Premier League showdown at the Emirates Stadium.
Manchester United have performed with zest and purpose under Ole Gunnar Solskjaer – in a stark difference to life under Mourinho.
The 56-year-old won two trophies during his time at Old Trafford in the form of the EFL Cup and Europa League crowns.
But the football was often lacklustre – and a far cry to the swashbuckling days of the Sir Alex Ferguson era.
And The Sun say Solskjaer laid into their sloppy display, accusing them of going back to the Mourinho days.
The Norwegian also reportedly told his team to use the international break to analyse their own performances.
And whether United can bounce back against Watford on March 30 is something only time will tell.
Solskjaer was, understandably, tetchy after the defeat to Wolves.
The FA Cup means a lot to the 46-year-old who lifted the prize twice during his playing days in 1999 and 2004 respectively.
And Solskjaer admitted his side had taken a step backwards after the chastening defeat at Molineux.
“Quite a lot was missing today, it was the poorest performance we’ve had, it was a big step backwards,” the United boss said after the game.
“We never had the urgency and quality on the ball even though without the ball in the first half we did ok.
“We felt too comfy in possession, we never managed to put their keeper or defenders under pressure.
“We had a couple of balls in behind for Rashford but not enough quality.”
Solskjaer did, though, praise Wolves for their defiant display.
“I think it’s something natural,” he added.
“You cannot perform to the top of your level every single time.
“It’s still against a good team, they’ve done really well against top teams, don’t take anything away from them even though we under-performed, so I don’t think that’s part of it at all.”