Van Persie had missed 11 matches through injury until starting in Tuesday's win against Cardiff and took only six minutes to get on the scoresheet. He lasted until just beyond the hour mark, when he was replaced by Wayne Rooney, who also returning from a lengthy absence.
"I’ve got them back and it's great to have them," Moyes told journalists on Friday at the Aon Training Complex.
"We're mindful they're both coming back from injuries and we have to make sure they’re ready [before we give them 90 minutes].
"We’re a little bit more concerned about Robin because he’s been out longer; Wayne’s been out for a shorter period. We have to keep managing them and do things right."
Moyes is hopeful van Persie's ruthlessness in front of goal will help turn United's form around.
"I think some of our performances have been quite good [but] we just didn't finish our chances.
"When you want to win you need people like Robin van Persie, who will get you the winning goal. The other night, we