BOURBONNAIS, Ill. -- For all the changes made on the defensive side of the ball, the key to the unit’s overall success might hinge on the health of 12-year veteran linebacker Lance Briggs.

The linchpin of the defense, Briggs started strong in 2013, but ended up appearing in a career-low nine games because of a shoulder injury that kept him on the inactive list for two straight months.

One of the best linebackers in franchise history, Briggs was voted to seven straight Pro Bowls from 2005-2011 where he developed the reputation as one of the hardest hitting linebackers in the league.

At 33-years old, can Briggs still elevate his game to a Pro Bowl level?

“I don’t know. I’ve lost a couple of steps,” Briggs said with a smile on Thursday. “Now sometimes I have to fall into a tackle. If I’m lucky, a tackle will fall, and I’ll put my hand on him and get credit for it. That’s where I’m at in [this] stage of my career.”

The Bears believe otherwise. The organization feels Briggs is the best striker on the defense and will look to the 12-year veteran to help lead a revamped unit that includes other proven older players such as Jared Allen, Charles Tillman, D.J. Williams, Tim Jennings and Jeremiah Ratliff.

“If [Lance] is playing at full-strength the way he started last season, we’re going to be a much better football team all around,” Bears head coach Marc Trestman said. “What he can do ripples through the entire team.”

Of course, there is the issue of Briggs’ expiring contract.

In the past, Briggs has gone public in expressing his displeasure with contract negotiations. He famously predicted he would never play another down for the Bears after the club slapped Briggs with the franchise tag in 2007. Briggs eventually signed a six-year extension in March, 2008 that the club later re-worked in 2012 to include another year and more guaranteed money.

However, Briggs said on Thursday he does not plan to make his contract a talking point this season.

“I’m not talking about a contract. I’m talking about playing football,” Briggs said. “I just want to play football. I’ve seen a lot of guys come and go. I’m here. I’m happy. I’m just appreciative.

“In a matter of one day, I learned that the coach that I’d been coached by for the last years was going to gone, and that whole staff was going to be gone. Everybody that I was used to everyday was going to be gone. The guy who I shared a room with for 10 years was going to be gone. A lot of the guys that I had built relationships with were gone. There’s some new guys coming in and filling up those numbers and those lockers. That’s life. That’s the way it is. It’s business.”

Briggs later reiterated that he wants to finish his career in Chicago.

“The only time I might not retire as a Bear was the time when I said I’d never put on a Bears’ uniform again,” Briggs said. “And I haven’t said that again since that time. So, of course [I want to retire as a Bear].

“I’m a Bear. I’m a true Bear. This is Year 12. I’ve given my blood, sweat and tears and my heart to the city and playing for this team. When it’s all said and done, I’ll retire a Bear.”