Van Persie picked up a calf injury on international duty with Holland after reporting for duty with a toe problem.
"We have a few with knocks," Moyes told MUTV.
"The one we are more worried about is Robin van Persie.
"He got a kick on the calf and he came off in the second game (against Turkey). He has had problems with his toes as well.
"We will see how he is."
Persie's hat-trick against Hungary last Friday took him top of the Dutch international scoring charts.
"It is an incredible achievement," said Moyes. "What he wants to do now is score more goals for Holland and do it in a World Cup when it matters.
"But there have been some brilliant Dutch forwards over the years and they have had an array of talent. To be at the top of that list is something special."
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