BELIEF IN THE BIRDS!!! TMZSports.com
Philadelphia roots are apparently thicker than blood in the Kelce household ... 'cause Fletcher Cox tells TMZ Sports he's sure Jason Kelce would cheer for the Eagles to beat Travis Kelce's Chiefs if they met in next month's Super Bowl.
A Philly showdown with Kansas City would happen if both teams pull out wins on Sunday ... and Fletcher is confident the Eagles will hold up their end of the bargain in a home tilt with the Commanders.