Sam Gallagher is a major doubt to face Manchester United after needing 12 stitches in his knee.

The 21-year-old Saints youngster was lining up for loan club Blackburn against Sheffield Wednesday but left the Hillsborough pitch on a stretcher following a challenge from Sam Hutchinson which infuriated Rovers boss Owen Coyle.

Gallagher was expected to line up against United in the FA Cup this weekend a week before his parent club play Jose Mourinho’s side at Wembley, but could now be ruled out for the tie.

Coyle fumed: "They should have been down to ten men in the first half.

"I've got young Sam Gallagher in there with 12 stitches from such a deep gash across his knee. I don't know how serious that injury is going to be.

"The referee is yards from it and he gives a yellow card. I found it beyond belief at the time and I'm 50-yards away because we all knew the seriousness of it in how it looked and how high the boy's studs were."