Donald Love is expected to make his first Manchester United start against FC Midtjylland on Thursday.
United have been hit by a series of injuries as they prepare for the round-of-32 Europa League match in Denmark.
The latest has seen them lose midfielder Marouane Fellaini after scans revealed a tear in his hamstring which is set to rule him out until the end of March.
Speaking at his prematch news conference, manager Louis van Gaal said his right-back for Thursday "has only played one game for us" -- a clear indication that Love is set to play.
The 21-year-old defender, who had not been in United's first-team squad before, came off the bench in the 2-1 defeat at Sunderland on Saturday when Matteo Darmian dislocated his shoulder.
Joe Riley, a 19-year-old who has not yet played for United, has a chance of featuring at left-back with Cameron Borthwick-Jackson ill, but Daley Blind could also be moved there.
Asked about his approach to young players, Van Gaal said: "They have played in the league, FA Cup and Europe, and that helps you develop more than playing for the reserves.
"We have young players sitting on the bench, and my belief is they can all play."
Darmian's injury had led Van Gaal to joke that United do not have any more full-backs and that he would have to "line up a 13-year-old guy or someone like that."