Manchester United boss Louis van Gaal is still unsure about striker Anthony Martial's availability for the crucial Premier League encounter against West Ham United on Tuesday night.

The 20-year-old Frenchman injured himself in the warm-up ahead of the 1-0 win over Norwich City on the weekend and van Gaal is unsure if he will be fit for the trip to Upton Park.

The Dutch manager said: "We have to wait if his muscle is still tight as I don't take any risks as he is a very important player.

"We don't want a rupture. That is very important for us."