Travis Kelce's traded the garden where he got engaged for the gridiron ... 'cause he was seen out just days after he and Taylor Swift made their announcement.
The NFLer hung out with his big bro, Jason Kelce, chatting it up on the sidelines of the University of Cincinnati and the University of Nebraska.
Check out the pic ... Travis and Jason are both repping UoC -- they both went to Cincinnati before beginning the pro careers that will land them both in the hall of fame one day.