Kelso played in eight NFL seasons and his entire career with the Buffalo Bills from 1986-1993. During his 1988 season, he intercepted 7 passes for 180 yards and one touchdown. Kelso appeared in four consecutive Superbowl's with the Bills. He was well known for wearing a "pro cap" on his helmet which was used
to reduce the risk of concussions.
As of the 2006 NFL season, Kelso serves as the color commentator for Buffalo Bills radio broadcasts on WGRF 96.9 FM. He is the Development Director (since 2003-2004) at Saint Mary's High School in Lancaster, New York,
as well as its varsity football defensive coordinator from the
2003-2010 seasons. Kelso also is a local baseball coach. Prior to that
he taught 6th grade at East Aurora Middle School.