NFL Ref Penalizes Chiefs Player for 'Excessive' Muslim Prayer 'Celebration'
Husain Abdullah retires from NFL over fear of suffering a sixth concussion, NFL News
NFL player Husain Abdullah 'gets penalty for praying' - BBC News
Husain Abdullah - Wikipedia
Chiefs Safety Husain Abdullah Announces Retirement, Cites Concussions
Regular Season Game 3 - Chiefs vs. 49ers (9-23-18) by Kansas City Chiefs - Issuu
Ex NFL Kansas City Chiefs' Husain Abdullah quits after suffering FIVE concussions
The NFL Can't Seem to Make Up Its Mind About CTE
Husain Abdullah retires from NFL - CougCenter
Former Chiefs, Vikings safety Husain Abdullah announces retirement
Other notable players who recently quit the NFL at age 30 or younger