Van Persie available for West Brom visit
The Dutch striker watched on from the sidelines with a thigh injury as United lost 4-1 to local rivals Manchester City last weekend, and also sat out Wednesday's 1-0 League Cup win over Liverpool.
However, the Scot revealed he will return at Old Trafford, although he may not start the match as he returns to full fitness, with Tom Cleverley also set to feature, despite suffering a knee injury earlier in the week.
"Robin will be back involved somewhere," Moyes said. "Whether we use him or whether he don't, he has trained today and is back fit.
"We will see exactly where he is but he has trained.
"Tom has done a bit of training today as well, he is not too serious. He sort of rocked his knee in training, and we were a bit worried, but he has had no reaction from it."
After such a disappointing result at the Etihad Stadium, Moyes promised the club's fans they will continue to see a reaction from his players, who are still hurting at their defeat against City.
"The players showed they were hurt and that they are determined to put it right," he added. "We are looking to show supporters they mean that, and try to make sure it doesn’t happen again.
"I have been learning every week since the day I walked in as Manchester United manager. I learned something the first day and I have continued to learn since.
"I don’t think that is going to change for a long time.
"I think if you are playing big games, that is part of it. This club has always played in big games, in big finals and games that really matter. The games this week mattered. In some of them, we did better than the others."