And they say he is not a main striker.
The England international had fluffed two of his last three from the spot and before the weekend had managed just two goals for Manchester United all season since the opening day.
But there is something about Chelsea. He has not matched the five goals he now has against them against any other team.
Although the perfect arc of a free-kick that found the top corner just as Chelsea threatened to come back into the match very much stands out on its own.
It was not just a great goal but an important one.
Ole Gunnar Solskjaer went to acknowledge the away support at the final whistle and was given a warm reception.
He knows the importance of dangling the scent of silverware before the United faithful – after all, it was the FA Cup that set his own boss Sir Alex Ferguson on an unprecedented glory trail after a slow start at OldTrafford.
Similarly, Frank Lampard was part of the Jose Mourinho phenomenon that may never have got started at Stamford Bridge were it not for their 2005 success in this very competition.
Yet last night the chance to give regular Premier League stars a rest and field a team packed full of youngsters was too strong for both of them.
An entirely forgettable first half hinged on a single moment of madness from one of the more senior United players who should have known better.
Marcos Alonso, 28, schooled at Real Madrid and a full Spain international, got himself the wrong side of Daniel James and should have let the Wales international teenager get on with running into a crowded area.
Instead, he challenged for the ball, allowed James to tumble over his leg, and referee Paul Tierney had little choice but to point to the spot.
Fair play to Rashford after his miss against Norwich on Sunday to accept the duties again. This time he sent Willy Caballero the wrong way to open the scoring.
Lampard needed to get his Chelsea charges back into the dressing room before they showed any real sign of mounting an appropriate response.
Callum Hudson-Odoi should have done better five minutes after the restart that scuffing a golden opportunity across goal from barely six yards out.
A better connection flew inches over the bar after 57 minutes as the home side continued to press, with United restricted to the occasional counter-attack.
In the end, though, it was Michy Batshuayi’s sheer determination that levelled the scores.
He ran hard from the half-way line, holding off any sort of challenge from the three United defenders who clustered around him.
Then, arriving close to the United penalty area, he drilled the ball low past Sergio Romero in the 61st minute for what was on balance a deserved equaliser.
United rallied, but neither side looked like making much headway as young limbs wearied and substitutions diluted the action rather than kick-starting it.
Until the 73rd minute, that is.
Rashford carefully placed the ball on the Stamford Bridge turf fully 30 yards from Caballero’s goal and looked up at what appeared little more than a half-hearted Chelsea wall.
His connection could not have been better, though.
He had been asked to be something of a leader for the even less experienced players around him. And yet he only turns 22 on Thursday.
He could not have delivered in more remarkable fashion.