Manchester United manager Louis van Gaal has admitted that he contemplated replacing Juan Mata just before the Spaniard struck the winning goal against Watford last night.

The Spanish playmaker, who was United's captain, struck the only goal of the game seven minutes from time to secure all three points for the home side at Old Trafford.

However, due to an injury, Van Gaal has revealed that the 27-year-old was close to being substituted before the match-clinching moment.

"Yes, that was true, because he was limping at that time," the United boss told reporters.

"But we were in a better moment, so I didn't want to change any more. I had changed the shape, put Anthony Martial in the striker's position and we were in a better shape.

"So I didn't want to make the change again and then Mata scored the goal, so I'm very happy that I let him stay on."

Mata did come off shortly after, with Paddy McNair being introduced to help shut out the game.