Van Nistelrooy, dapper in a turtleneck, dark jacket and trousers ensemble, set out his manifesto to take on Leicester, who arrived two points and a place – 15th – below United in the league: “Hopefully lots of possession and attacks. That’s what Man United is about.”

Joshua Zirkzee, one of three changes, could do precisely this when roving in but, as is the faultline in his game, the wrong option was chosen, and the Foxes escaped.

But then Casemiro’s thunderbolt had Van Nistelrooy “oohing” and raising his arms. United’s build-up was neat, Leicester’s lack of pressure on them a dereliction. Through an inside left-channel, Lisandro Martínez found Alejandro Garnacho, who skipped infield and tapped to Bruno Fernandes. The captain, as he cutely does, let the ball roll and the Brazilian had an age to fire past Danny Ward into the top right corner. This broke a vibe that had been oddly becalmed, a mood that soon again settled for a period. Then, a second home strike ratcheted spirits once more. Casemiro, this time, ignited the move, locating Dalot along the right. He shifted his body to face the ball and sliced in a cross that was smashed in by Garnacho.

Cut to a pained Steve Cooper in his technical area, who was booked for protests that Dalot was offside – and his despair nearly deepened when Fernandes lined up a shot from the edge of the area. But the No 8 plumped, instead, for a no-look pass and he misdirected.

United, basically since Sir Alex ­Ferguson retired in May 2013, are experts at shooting themselves in the proverbial. This did not change under their second Dutch manager of the season: Altay Bayindir, the third of United’s fresh personnel, flapped at a cross, the ball went to Bilal El Khannouss, and he scored via pinball off the left post.

The prospect of another United collapse lasted six minutes – the span in which Fernandes and Casemiro registered. El Khannouss tripped over Garnancho and Fernandes flipped a deflected free-kick in past Danny Ward; then Casemiro touched home the rebound off both Leicester posts – their left one first – after his own header from a Rashford delivery.

All fine and dandy for United until, in first-half added-time, a Casemiro and Dalot mix-up and Conor Coady bundled in to give Van Nistelrooy something to chew on at the break.

Despite the caretaker fielding a second No 6 in Manuel Ugarte, the gaps in the United midfield that are an unwanted Ten Hag legacy remained and Cooper’s unit ran through these in several concerning attacks.

Van Nistelrooy, in the technical area, met these and other sloppy United play with obvious disquiet. The worst featured James Justin getting in behind and crossing, a flailing Casemiro blocking, and, at the ensuing corner, the latter ­heading to safety. More came, often from the boots of the firefly El Khannouss whose smart wing play had United in disarray. Then, at last, a slick United raid of the half that ran through Fernandes-Rashford-Fernandes-Zirkzee-Garnacho and ended with a Zirkzee fingertip-warmer for Ward.

And then came United’s fifth. A Fernandes-Rashford combo caused a Caleb Okoli brain-freeze that resulted in Fernandes being clean through. A dummy took Ward to ground and the 30-year-old was never going to miss from inches away.

United cruised. Off came Rashford and Martinez, on came Amad Diallo and Noussair Mazraoui. Ugarte, United’s Red Adair, morphed into a schemer pivoting and spraying an aerial ball to Fernandes down the left. It was, for United, a rare thing: this type of night.