Fraser Forster has left the England squad to return to Saints after picking up an injury.

The Saints goalkeeper was expected to start Sam Allardyce’s first game in charge against Slovakia in a World Cup qualifier on Sunday night, but has instead been forced to return to Staplewood.

Forster’s injury is not believed to be serious, but the club’s medical staff will assess him and decide upon a treatment programme.

They will also discover whether the injury is likely to sideline him from first team, and, if so, for how long.

If Forster is out then Alex McCarthy will have to take over between the sticks for the trip to Arsenal a week on Saturday.

McCarthy was signed this summer from Crystal Palace as cover for Forster should the keeper be ruled out for any period of time.

He did at least get a match under his belt as he played against Charlton in the Checkatrade Trophy on Tuesday night.

Saints last week brought in Stuart Taylor, the former Arsenal and Manchester city keeper, on a free transfer to act as the third choice keeper.

He would find himself on the bench at the Emirates if McCarthy started in place of Forster.