Manchester United youth team player Phil Marsh was airlifted to hospital with a broken leg after a car crash near the club's training ground.
The club said the 17-year-old is in a stable condition after also suffering an arm injury and facial cuts and bruises.
Team mate Callum Flanagan, 18, was also in the car but escaped without any significant injuries.
Both players featured as substitutes in United's FA Youth Cup win over Manchester City on Tuesday, Flanagan scoring the second goal in a 2-0 victory.
As a result of the accident, which took place close to the club's training ground at Carrington, a few miles west of Manchester, United called off a reserve team match against Birmingham City scheduled for Wednesday.
United reserve team player Jimmy Davis was killed in a road accident last August while on loan at first division Watford.