Kansas City, Mo. ? After nine years in the NFL, Chiefs defensive end Mike DeVito is calling it quits.

The 31-year-old DeVito, who announced his retirement on Twitter on Monday, said his wife, Jessie, helped him reach the decision.

“When I look at it, my wife was the biggest reason — she helped me break down the process and think it through,” said DeVito, who expressed interest in continuing his football career as recently as a month ago. “I do love the game of football and I’m thinking about all the guys I’ll miss and that locker room and the coaches.

“But I have people here that will expect me to be here and be a father and be a husband and a leader of my family.”

DeVito wants to believe he could have helped the Chiefs again as a rotational player, but at the end of the day, the combination of his age and the two concussions he suffered last year were enough to convince him to hang them up. DeVito made it clear he feels great, but his wife did not want him to put himself at risk for another concussion.

“I know what we signed up for — it’s a physical game, that’s part of it,” DeVito said. “At the same time, I can come back from a knee injury and an Achilles’ injury but concussions start changing who you are, and with the effects you can have immediately and down the line, you have to think about it.”