The striker has made an instant impact at Old Trafford following his move from Arsenal, scoring eight goals in 12 games.
However, Giggs believes that the Dutchman's assists have also proved valuable to the side.
"Robin's set piece delivery has been really important to us," the 38-year-old told the club's official website.
"It's a big plus this season that we're scoring from set pieces and corners. That's something we haven't done over the last few years as often as we'd have liked.
"So with Robin it's not just goals you get. He's helped add more goals to the scoresheet and helped a few different names get on there."
Van Persie is expected to start against his former club when Arsenal travel to Old Trafford in the Premier League on Saturday.