James Harrison is calling it quits after 15 seasons in the NFL.

The former Steelers linebacker, who turns 40 in May, announced his decision to retire Monday in an Instagram post that featured pictures of his children, NBC Sports reported.

“I’ve missed way too much for way too long…and I’m done,” Harrison wrote. “Many thanks to my family, coaches, the fans, and everyone who played a role in my football life.”

Harrison was released by the Steelers last December, and immediately signed with the Patriots heading into the playoffs and Super Bowl LII. After taking the field for just 40 snaps in 14 games with Pittsburgh last season, Harrison played 69 snaps in Super Bowl LII against the Eagles. He tallied 11 tackles and 2 sacks in four total appearances with the Patriots.

Harrison hinted at his approaching retirement in an interview with ESPN last year.

“I told my son [James III] he could play contact football when I stop, so I’m going to have to give it up in the near future,” nhe said. “So he can start getting adjusted to playing. I don’t want him to wait too long.”

Harrison holds the Steelers franchise record for sacks with 80.5 in 14 seasons. He signed with Pittsburgh in 2002 as an undrafted rookie, then did brief stints with the Baltimore Ravens and NFL Europe’s Rhein Fire in 2003. He returned to Pittsburgh in 2004, where he was selected to the Pro Bowl for five straight seasons from 2007 to 2011 and won the NFL’s Defensive Player of the Year in 2008.