United already deserved to be ahead but Derby threatened on the break and almost made them pay with a header from the unlikely source of Marcus Olsson. The 5ft8in full back leaped to meet Johnny Russell’s floated cross from the left with a looping attempt that Sergio Romero was forced to tip over. When Pearce went close from the subsequent corner, it was a reminder to United that they still had much work to do.
The Frenchman appeared to have been given freedom to press forward by Mourinho and it helped United, who were dominant for much of the opening 45 minutes and should have entered the break ahead. Their best opportunities fell to Marcus Rashford, auditioning in the lone striker role with Lukaku on the bench. The youngster should have done better with his first sight of goal, but dipped a venomous shot over after initially doing well to win a 50/50 with visiting defender Alex Pearce.
How would Manchester United’s last few weeks have panned out if Jesse Lingard was not enjoying the finest form of his career so far?
The audition was over. At half time, Mourinho shifted Rashford to the left, replaced a woeful Mkhitaryan and brought Lukaku on through the middle, less than a week after he was stretchered off the Old Trafford pitch wearing an oxygen mask and with head injury, but the change did not have an immediate effect.
Derby County (4-2-3-1): Carson; Wisdom, Keogh, Pearce, Olsson; Thorne, Huddlestone; Weimann, Lawrence, Russell; Winnall.
Referee: K Friend (Leicestershire)
United resumed control after that scare but, save the industrious and inventive Pogba, they did not do enough to create clear openings. Rashford at least looked livelier in a role on the flanks and as the match entered its closing stages, he struck the base of the post once again. This time, it was no easy chance, with the youngster having cut inside from the right and manufactured space for the shot. He was unlucky to see it bounce back to him off the upright.