NFL's Abdullah Announces Retirement

Free-agent safety Husain Abdullah announced Monday that he has decided to retire, posting on Instagram that his health was the primary deciding factor after suffering five concussions in his seven-year career.

Abdullah thanked the Minnesota Vikings for signing him as an undrafted free agent in 2008 and called his three seasons with the Kansas City Chiefs "the most enjoyable football experience in my entire life."

Numerous productive players have indicated plans to retire this offseason, including Detroit Lions wide receiver Calvin Johnson and New England Patriots linebacker Jerod Mayo. Many of them have cited their long-term health as one reason behind their decisions.

The 30-year-old Abdullah had been a valuable defender for the Chiefs since he joined the team as a free agent in 2013. Kansas City used Abdullah, a part-­time starter over his three seasons, in a variety of roles. He was effective as a blitzer, though he had just a half-­sack with Kansas City, and was used a lot in man-­to-­man pass coverage.

Starters Eric Berry and Ron Parker along with Daniel Sorensen are the remaining safeties from the five who played significant snaps for the Chiefs last season. Kansas City has moved cornerback Jamell Fleming to safety and signed Jordan Kovacs from the Miami Dolphins, while Tyvon Branch signed as a free agent with the Arizona Cardinals.

Colts Owner Irsay Says Not Much Known About Side Effects of Playing Football

Indianapolis Colts owner Jim Irsay told the Sports Business Journal that players understand they are taking a risk playing football, but said much is not known about side effects of participating in the sport, comparing it to the varying side effects one might experience from taking aspirin.

Irsay made his comments to the publication at last week's owners meetings in Boca Raton, Florida. The Sports Business Journal published excerpts from the conversation with Irsay on Monday.

According to the Sports Business Journal, Irsay referred to bobsledding several times during the interview as a sport that, like football, poses dangers to its participants.

But, like taking an aspirin, much is not yet known about the side effects of playing, he said.

"I believe this: that the game has always been a risk, you know, and the way certain people are. Look at it. You take an aspirin, I take an aspirin, it might give you extreme side effects of illness and your body ... may reject it, where I would be fine. So there is so much we don't know," he told the Journal.