The 18-year-old striker has impressed in United’s junior sides this season, scoring three times at Under-19 level and also finding the net regularly for the Under-21 team.
His breakthrough into the senior side, though, has surprised even the most optimistic of United supporters, with four goals in his first two games.
Having struck twice in a Europa League win over FC Midtjylland last Thursday, Rashford followed that up with two more in Sunday’s 3-2 Premier League victory over Arsenal.
Manager Louis van Gaal is wary of asking the Manchester-born forward to take on too much responsibility too soon, but leaving him out against Watford may well prove impossible.
Even so, Van Gaal is urging caution.
“We have to wait and see with Marcus,” he said. “He has only played two matches. It is about consistency. He has to show it in the third and the fourth and the fifth game.
“But what he has shown in the second match is already an improvement on the first and that is special.”
Rashford is not the only young player to break into the United side in recent weeks.
Defenders Donald Love, Regan Poole and Timothy Fosu-Mensah have also been given debuts since the beginning of February, as have midfielders James Weir and Joe Riley.
To a certain degree, Van Gaal’s hand has been forced by a long injury list.
Rashford was only given a chance because of a hamstring injury to Anthony Martial, with United short of options in attack as Wayne Rooney recovers from the knee injury that is set to keep him out until April.