Free agent outfielder Josh Willingham has announced his retirement after 11 MLB seasons.

Originally a 17th round draft choice in 2000 by the Florida Marlins, the 35-year-old also had stops in Washington, Oakland, Minnesota and Kansas City.

In 2009, with the Nationals, he became the 13th player in MLB history to hit two grand slams in the same game.

"I felt like it wouldn't be fair to myself, and more importantly to the team that was paying me a lot of money to perform at a high level, if there was a chance my dedication would waver -- particularly as the season got longer," Willingham told ESPN. "I'm honored to have played for as many years as I have, and I feel even luckier to walk away on my own terms instead of having the decision made for me."

He has career batting average of .253 with 195 home runs and 632 RBIs.

Willingham was awarded the Silver Slugger Award in 2012.

Last season, Willingham made the playoffs for the first time in his career after he was acquired by the Royals from the Twins. He batted .250 in four pinch-hit appearances.