Not sure. But yeah, van Persie might be the most vocal one. Rooney is certainly shy and quite.
Anyway, I personally think people put too much emphasis on the captaincy thing. After Roy Keane left, we had Gary Neville, Giggs, Rio and later on Vidic & Evra as well, all of them were vocal and commanded huge respect in the dressing room and the pitch. We don't have characters like that anymore. Rooney and Fletcher have been made captain and vice-captain respectively, only because they are the most senior players and have been here for many years.