He did alright when he came on. That's good for him. However, for me at least, I expect a striker who plays for Manchester United to take that shot on themselves at that particular moment of the game. It's all about being brave, confident, and good enough to take on that burden and responsibility. Passing it to another player in space (a centre back, no less) is fine...as long as that pass is sensible and gives them the easy job of just slotting it away.
Trying not to be too harsh, but I 100% expect a striker of ours to go for that themselves. Worry about the offside matter later on, but he has to take that on.