The England star, 26, suffered a deep gash in his leg after coming on as a sub for Man Utd against Fulham a fortnight ago.
There were fears the striker could be out for as long as two months, but Rooney believes his recovery is on track.
He said: “The injury is going well. It could have been a lot worse than what it was. It is up to the doctor. When he declares me fit I will be ready.
“It feels good at the minute. The timescale put on it was four weeks. If that is the time they feel I need for the wound to heal properly then that is what I will do.
“What I don’t want to happen is to come back too early when it is not quite healed and it opens up again first game. That would just set me back again another four weeks.”
He added: “Overall, I think at the most I will miss four games.”
A four-game lay-off might mean he is available for the Capital One Cup tie against Newcastle on September 26.
Amazingly, Rooney says his gruesome injury — caused after being caught by Hugo Rodallega’s boot — was not painful at the time.
He said: “It didn’t hurt me at all. I got up ready to play on. I was holding my leg up to the referee to say I needed a physio or doctor on.
“I just didn’t want to go off on the stretcher.
“I said to the doctor I can walk off. But he told me it was too dangerous, so he told me to get on it!
“My lad was in the crowd and I didn’t really want him seeing me carried off on a stretcher.”
When Rooney does return to action he will be able to start building a partnership with stellar signing Robin van Persie.
He said: “I am looking forward to getting back into the team and trying to forge an understanding with him.”
Rooney is currently promoting his latest autobiography, My Decade in the Premier League.
In the book, he admits handing in a transfer request two years ago was the biggest mistake of his career.
Rooney issued a statement in September 2010 in which he questioned United’s ability to attract top players and indicated he wanted to leave.
Two days later, though, he performed a dramatic U-turn and signed a new five-year contract.
He wrote: “In September 2010 my ankle puts me on the sidelines.
“I get frustrated with myself, my game, my injury, and everything around me.
“I’m stuck in a cycle of bad form but I can’t get out of it.
“And that’s when I make the biggest mistake of my football career.
“In October, I release a statement which publicly questions my happiness at Old Trafford. Am I better off elsewhere?
“Everyone makes a fuss. There are discussions inside United to sort out the issue, people outside United chuck their opinions around, but the thing is, nobody really knows what’s going on in my life.
“None of them understand where I am in my career. They don’t know where my head’s at.
“The only person who really knows what’s going on in there is me, but even I’m not sure what I want.”
He continued: “Then the manager has his say. ‘Sometimes you look in a field and you see a cow and you think it’s a better cow than the one you have in your own field. And it never really works that way’.
“He’s saying the grass isn’t always greener, and he’s right.
“I like what’s in my field. I’m wrong. United want the same as me: trophies, success, to be the best.”
