Kroy Biermann says he's keeping himself in shape and wants to return to the NFL this season ... despite being cut by the Buffalo Bills last month.
Kroy -- along with his wife, Kim Zolciak, and daughter, Brielle -- were at LAX when the 31-year-old linebacker told us he's definitely not ready to retire.
By the way, Brielle is dating Boston Red Sox pitching prospect Michael Kopech -- who threw a 105 MPH FASTBALL back in the summer. Dude's a stud.
So, we asked how he's getting along with Kroy -- sounds like things are moving in the right direction.