Roger Federer's back could impact U.S. Open resultsSI executive editor Jon Wertheim shares whether Roger Federer or Rafael Nadal is the favorite in this year's U.S. Open.SI Staff|Share on FacebookShare on XAdd us as a preferred sourceSI executive editor Jon Wertheim shares whether Roger Federer or Rafael Nadal is the favorite in this year's U.S. Open.Add us as a preferred source on GoogleFollowLoading recommendations... Please wait while we load personalized content recommendationsPublished Aug 24, 2017 | Modified Aug 24, 2017SI STAFFShare on FacebookShare on XHome/Tennis