Dolphins RB Arian Foster announces retirement

— -- Miami Dolphins running back Arian Foster is calling it quits.

Foster released a letter on his decision to retire via The Uninterrupted on Monday.

"There comes a time in every athlete's career when their ambition and their body are no longer on the same page. I've reached that point," Foster wrote.

Foster was a four-time Pro Bowler for the Houston Texans before signing with Miami. He finishes his career with 6,257 rushing yards and 54 touchdowns.

"This game has been everything to me ... my therapy, my joy, my solace and my enemy. I've learned to love every facet of this game, from the peak of accomplishment to the gutter of criticism, " Foster wrote.

The Dolphins signed Foster to a one-year, $1.5 million contract one week before training camp. The team met with Foster in the spring to get an update on his Achilles rehab and kept him on the short list.

Foster won the starting job during the preseason, but his tenure as the starter lasted just two games. Foster injured his groin and a hamstring in Miami's Week 2 loss to the New England Patriots and missed the next three games.

By the time Foster returned in Week 6, he didn't look the same, and Jay Ajayi made significant strides as the starter. Ajayi became just the fourth player in the Super Bowl era to post back-to-back 200-yard games against the Pittsburgh Steelers and Buffalo Bills.

Barring injury, Foster likely would have been a backup the rest of the season had he not retired. Foster also made headlines this season as one of three Dolphins players, along with receiver Kenny Stills and safety Michael Thomas, to take a knee during the national anthem before every game.