Education
Callahan attended Cy Woods High School(212°) where he played football.
Callahan attended Cy Woods High School(212°) where he played football.
He played college football at Rice University. Callahan signed with the Bears as an undrafted free agent in 2015. Callahan was named to the 5A All State First-team and Dave Campbell"s Texas Football"s 2009 All-Texas High School team
Chicago Bears
On May 2, 2015, Callahan signed with the Chicago Bears as an undrafted free agent following the conclusion of the 2015 NFL Draft.
On September 22, 2015, the Bears waived Callahan. On September 24, 2015, the Bears re-signed Callahan for the practice squad.
On January 3, 2016, Callahan recorded his first career sack against the Detroit Lions.