D'Qwell Jackson has seen the good and bad that comes with a long NFL career.

There have been record numbers and devastating injuries.

Right now, though, he's just happy to be in Indianapolis.

The Colts are happy, too.

Jackson might not have been the most coveted free agent on the market when Indy signed the former Cleveland Browns linebacker in the offseason, but his arrival has helped reinforce the team's run defense and point things in the right direction.

"It was my first time being on a new team in eight years, so you have your doubts," Jackson said. "But the first day I stepped into the building, they embrace you."

Jackson is making an impact as a starter on a defense that has improved significantly despite losing players to injury and suspension.

Jackson had a season-high 10 tackles and forced a fumble against Jacksonville. He recovered a fumble against Houston and had seven tackles last week in a shutout victory over Cincinnati.

The Colts plan to show the same grit this weekend at Pittsburgh.

For Jackson, however, the trip too Heinz Field is a reminder of when he faced the lowest point of his career.

He suffered a season-ending pectoral injury against the Steelers five years ago and, later, during training camp before the final year of his rookie contract, he tore a second pectoral muscle that kept him out of the 2010 season.

Colts safety Mike Adams was also a teammate of Jackson's in Cleveland and remembers how bad it got after the second injury.

"He was the heart and soul of the defense," Adams said. "He was young, but he still had that presence that everybody respected, and we needed him."

Adams had watched Jackson put in the time and effort each day for nearly a year to make a return only to face another injury. Jackson felt as if he let people down, especially his family while also struggling through a divorce.

The only thing Adams could do was encouraged his long-time friend to "keep grinding."

"It was taxing," he said. "I didn't know if I was going to have a job again. So, I corrected a lot of things in my life. I made a deal with myself, 'Either you do what it takes now, so that if it doesn't work out, I can live with myself or it was going to work out.'"

Jackson saw some success in Cleveland. He hasn't missed a game since returning in 2011 and in his first season back he finished No. 2 in the NFL with 158 tackles. He previously led the league with 188 tackles in 2008.

Now he is showing the Colts what he can do and while working to gain the respect of his new teammates.

But Jackson made one thing clear.

"I want to end my career here," he said. "I haven't even been here a year. I'm doing everything I can to make sure if I can't end my career here, it's going to be a tough decision for those decision-makers to get me out of here."

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