Manchester United manager Louis van Gaal gave his backing to misfiring striker Radamel Falcao, after watching former player Danny Welbeck knock his side out of the FA Cup on Monday.

Manchester United manager Louis Van Gaal spoke after his side's FA Cup quarter final defeat to Arsenal and admitted Angel Di Maria shouldn't have touched the referee.

Manchester United have been given an injury scare ahead of Sunday's game against Tottenham after Ashley Young limped away from Old Trafford following the 2-1 FA Cup defeat to Arsenal, sources have told ESPN FC.

United will already be without one winger for the visit of Spurs, rivals for a top-four finish, as Angel Di Maria is suspended after his red card against the Gunners.

Young, who completed the 90 minutes against Arsene Wenger's side, could be a doubt as sources saw him hobbling after United's FA Cup quarterfinal exit.

When asked how bad the problem was, the former Aston Villa man would only say: "We'll see."

The 29-year-old scored the winner in United's last league game, away at Newcastle, and has been in fine form this season.

He has already had two spells on the sidelines this season with groin and hamstring injuries.

In Di Maria's absence, Adnan Januzaj could be given his first start for more than a month.

Juan Mata, who has only played 23 minutes in the last seven games, Radamel Falcao -- who has been on the bench in the last two -- and Michael Carrick, who has not begun a match since January, are all options to come into a rejigged side.

As well as Di Maria, who serves a one-match ban for his dismissal, United are also definitely without suspended defender Jonny Evans.

Striker Robin van Persie, who has an ankle injury, is not expected to be fit.

Information from the Press Association was used in this report