What It Means:

"There are numerous deciding factors in my decision, with personal health being foremost. Sitting for five weeks last year after suffering the fifth concussion of my career, I had a lot to contemplate," Abdullah said on Instagram. "My goals moving forward are to be of benefit to my family, my community, my country and hopefully the world. Having a sound mind will be vital in accomplishing these goals."

Only 30, Abdullah is yet another quality player retiring early due to concussion concerns. An undrafted free agent out of Washington State in 2008, Abdullah played just 53 snaps his first two seasons in the league. He earned a starting spot with the Minnesota Vikings in 2010 and started 45 games for Minnesota and Kansas City over the next five seasons. Abdullah finishes his career with six interceptions, 2.5 sacks and 261 tackles. The Chiefs, built on defense, ranked fifth in Adjusted Defensive Net Expected Points per play last season.