Ole Gunnar Solskjaer says Mason Greenwood would have earned a call-up to the first-team this week had he not been injured.
Solskjaer has lost Anthony Martial and Jesse Lingard for up to three weeks, but injury has also delayed the debut of 18-year-old Greenwood.
Speaking in his pre-match press conference before Monday's FA Cup fifth-round tie with Chelsea, Solskjaer said: "I think they'll be out for two-to three weeks, then you're looking at young players, Mason Greenwood is your time to step in and he's injured.
Unfortunately, out for a couple of weeks as well, sometimes that's how the luck goes but Mason will get his chance."