Indianapolis Colts linebacker Robert Mathis, 35, will retire after Sunday's game against the Jacksonville Jaguars after 14 years with the organization, he announced during a news conference Friday.

"Put a cap on a blessed career," Mathis said. "Something I would have never imagined that would come to pass. Severely blessed, fortunate. God has been good to me."

Having played for the Colts since 2003, veteran linebacker Robert Mathis is retiring. Zach Bolinger/Icon Sportswire

He later posted a message to Instagram, saying, "Since 2003, you guys, you've embraced me, you loved me and you accepted me. And I'm here to say thanks, I love you guys, and I'm a Colt for life. I bleed blue, through and through."

🎉👍🏿✌🏿🎉😎😢 Love Y'all A video posted by Robert Mathis (@rmathis_the1st) on Dec 30, 2016 at 10:02am PST

Mathis, who was selected in the fifth round out of Alabama A&M in 2003, spent his entire career with the Colts. He was outspoken in saying that he played with a chip on his shoulder because critics said he went to a small college, was too small and wasn't quick enough to chase down quarterbacks in the NFL.

That chip worked for Mathis because he's heading into Sunday's game as the Colts' franchise leader in sacks (122) and has an NFL-record 40 career strip sacks. His best season was in 2013, when he had 19.5 sacks.

"Robert is kind of that quiet guy that doesn't speak a whole lot, but when he speaks and says something, it's just straight gold," kicker Adam Vinatieri said. "He came to work every day and became a superstar through hard work. He's awesome."

Mathis said he made the decision to retire a few weeks prior to the Nov. 6 game at Green Bay. He notified his teammates about his decision Friday.

"It's time to step aside," he said. "Game has been good to me. I want to pay it forward. I want to leave it better than I found it. And injuries, I want to walk away. I don't want to limp away. Rest of my body goes to my kids."

Quarterback Andrew Luck said Mathis was the best teammate anyone could ask for. "He's very motivational to be around," Luck said. "Everything he does is team-first. He's a great leader."

Mathis missed all of the 2014 season. He served a four-game suspension for using performance-enhancing drugs and then missed 12 games with a torn Achilles.

Mathis, who has four sacks this season, is tied with Simeon Rice for 18th in NFL history in sacks.

"He is a guy that nothing was given to him, he earned his way into this league and he has never taken it for granted, not one day." Colts coach Chuck Pagano

"All that he does inside this building and all that he does outside this building for the community, he is a warrior, they don't make them like that," coach Chuck Pagano said. "I wish they all had his drive and his passion, his love for the game and his toughness and durability, coachability, tenacity, resolve and everything.

"He is a guy that nothing was given to him, he earned his way into this league and he has never taken it for granted, not one day. He never let any of the success or fame or money or this, that and the other ever get to him. He has been the same guy for 14 seasons. He looks at it as a privilege and not a right. So many times you find it the other way.

"I wish they all got it and figured it out like he figured it out and came with that gratitude every single day."