The Gunners hitman has scored 22 goals in all competitions this season, while Rooney has netted 18 times.
"It is not about me and Van Persie," said Rooney. "It is about us against Arsenal. That is what we will be focusing on.
"There are a lot of top strikers in the league; Van Persie, Sergio Aguero, Yakubu is playing really well.
"[Van Persie] will be the biggest threat for Arsenal on Sunday. Van Persie and Ramsey are certainly the two who have stood out for them this season."
United beat Arsenal 8-2 at Old Trafford earlier in the season.