The England striker is suffering from an ankle problem at the moment, but he insists that he will get back on form when he returns to the United frontline.
He told reporters: "I'm only a human being. I hurt as well, but I need to get through this and get back to playing football the way I can do.
"I know I can play better, so I'm hoping to get a consistent run of games in the team. If I do that, I'm sure my form will be back to its best.
"When you're not playing at your best, you need to just continue playing and doing the simple things, then your form will come good.
"You always want to play well and give the manager no excuses to leave you out, but there are top players here, so you have to be at your best to keep your place.
"If you're not, the manager has the players to leave you out. All footballers get left out at some stage, but I want to play every game.
"My performances could be better. I obviously missed pre-season and I've only played four or five games this season, but the more games that you play, the better your form will become, so I'm hoping to get a run of games."