Kansas City Chiefs safety Husain Abdullah is calling it quits after spending seven seasons in the NFL.
Abdullah cited health concerns as playing a major role in his decision, having suffered five concussions during his time in American football.
The 30-year-old - who played for the Minnesota Vikings before arriving in Kansas City - took to social media on Monday, writing via his official Instagram account: "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. 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."
Abdullah said last season he suffered his fifth concussion, and his first four came in a flurry.
At one point in his career he had four concussions in 15 months, with the last one ending his 2011 season.
After that, Abdullah seriously contemplated what to do next, and took a year off from football to complete a personal journey.
Instead of playing football, he spent the 2012 season taking a Hajj (Islamic pilgrimage) to Mecca. He made the trip, which is a mandatory religious duty, with his brother Hamza Abdullah, who was also in the NFL.
When he returned, Abdullah signed a one-year contract with the Chiefs, playing in all 16 games. He re-signed with them the next season and made headlines when he was penalized after giving an Islamic prayer. The NFL said later he should not have penalized.
"The Kansas City Chiefs will forever have a special place in my heart," Abdullah added.
"After sitting out of football to fulfil my Hajj Pilgrimage in 2012, The Chiefs were the first to call. The three years I spent playing for KC may have been the most enjoyable football experience in my entire life. Thank you."