LONDON (AFP) - Manchester United manager David Moyes has admitted that winger Ashley Young is set for a spell on the sidelines with an injury suffered in the New Year's Day defeat by Tottenham Hotspur.

The Englishman hurt his shoulder in a collision with Tottenham goalkeeper Hugo Lloris that Moyes insisted should have led to a penalty for his side.

The former Aston Villa player landed awkwardly as he leapt over Lloris and will certainly miss Sunday's FA Cup third-round meeting with Swansea City.

"Ashley has got an injury that is going to keep him out for a time," said Moyes.

"It is a shoulder injury he received in the challenge by the goalkeeper. I am not sure how long it will be."

Meanwhile, Moyes offered no further update on the fitness of Robin van Persie, who has missed six games with a thigh injury.

"We will let you know when he is ready," said the Scot.