Marcus Rashford missed Aston Villa's 3-0 FA Cup semifinal defeat against Crystal Palace after picking up an injury that "could rule him out for the rest of the season."
The forward was not named in Unai Emery's starting XI to face Crystal Palace at Wembley on Saturday with Villa saying he had picked up "a knock."
The news will come as a blow to Villa's hopes of a top-five finish in the Premier League and subsequent Champions League qualification. They are seventh but only three points behind Chelsea who are fifth and five back from Newcastle in third with four games remaining.
"He's injured," Emery said. "He got injured this week and [Friday] we did a test. It's his hamstring. We are going to try to test him each match but he's injured and probably some weeks he won't be available."
Rashford sustained a minor muscle injury during the first half of the 2-1 defeat to Manchester City on Tuesday.
The 27-year-old, who scored a first-half penalty at the Etihad Stadium, was able to continue after the break before he was replaced with Ollie Watkins after 76 minutes.
Watkins took Rashford's place in the Villa team at Wembley. Rashford, who moved to Villa Park on loan from Manchester United in January, has been a regular in Emery's team.
He has started nine of Villa's last 12 games including both legs of the Champions League quarterfinal against Paris Saint-Germain.
Rashford's future is up in the air. He is due back at United in the summer although a source has told ESPN that he does not believe he will play for the club again while Ruben Amorim remains manager.
Villa have a £40 million ($53.2m) option to make his move permanent, but Rashford would still have to agree personal terms.
A source told ESPN that the England international is targeting a move to a Champions League club for his next move.