The 22-year-old forward, who sustained a stress fracture to his back, was not named in the squad that played Liverpool at Anfield on Sunday.
Marcus Rashford could be on the sidelines for a few weeks due to a back injury, according to Manchester United manager Ole Gunnar Solskjaer.
The 22-year-old forward, who sustained a stress fracture to his back in Wednesday's 1-0 FA Cup win against Wolverhampton, was not named in the squad that played Liverpool at Anfield on Sunday.
Speaking prior to the game, Solskjaer told Sky Sports: "He got a couple of knocks again, jolts when he came on against Wolverhampton, and he's aggravated his back.
"He's had some trouble before. We're going to give him time to recover and rest before we put him back on the pitch.
"He's always recovered quickly before, so let's hope he does that again.
"I wouldn't expect him to be back in the next few weeks. We've got a mid-season break, but I'm not sure we're going to see him before then."