INDIANAPOLIS — Colts linebacker Robert Mathis has learned a few things being in NFL locker rooms for the past 12 years.
Ignore conventional wisdom, work relentlessly to prove the doubters wrong and play it safe when dealing with an injury.
Less than 24 hours after team owner Jim Irsay tried to tamp down the early-season expectations for the 2013 NFL sacks champion, Mathis reluctantly acknowledged that he would accept the third part of the lesson while maintaining his goal of lining up for the Colts' regular-season opener Sept. 13 at Buffalo.
"I want to be out there with my guys, I want to be out there and be part of it," Mathis said after the Colts completed the last of their offseason workouts Thursday.
Nobody questions Mathis' desire to come back after missing all of last season. It's the circumstances that have raised questions.
Coach Chuck Pagano held him out of all four preseason games last year after the league announced Mathis would miss the first four regular-season games for using a performance-enhancing substance. He missed the final 12 games after tearing his left Achilles tendon while working out on his own during the suspension.
Many wondered whether the 34-year-old Mathis would recover from an Achilles injury and regain his old form. If that wasn't enough of a challenge, there is this: Mathis acknowledged Thursday that his recovery indeed hit a "snag," though he downplayed the significance of the setback.
Mathis has spent his entire football career defying the odds.
The Atlanta kid who was overlooked by all the big colleges finished his career by setting the Football Championship Subdivision's single-season record for sacks (20) in 2002. Then the Alabama A&M alum wasn't supposed to be big enough to hold up in the NFL. And when Pagano switched from the Colts' traditional 4-3 defense to the trendy 3-4 in 2012, critics contended Mathis couldn't make a smooth transition from defensive end to standup linebacker so late in his career.
Wrong, wrong and wrong. Mathis got his first career interception in 2012 and led the league with a franchise record 19 1/2 sacks in 2013.
"I was always just too something to not get the job done," Mathis said. "So I've got to get the job done."
The Colts' complex is filled with cautious believers.
Pagano and general manager Ryan Grigson have continued to talk about taking it slowly with one of the NFL's most feared pass rushers. Irsay added to the discussion Wednesday night when he said Mathis probably would not be healthy enough to go full throttle when training camp workouts begin Aug. 2.
Mathis understands. He's walking with a slight limp, did not run in last week's charity softball game that he co-hosted and even though he says doctors have cleared him to do pretty much everything, the Colts have kept him out of all of the on-the-field work this offseason.
"It's frustrating because I'm used to going 100 mph or whatever, but I'm at a point in my career where you have to be smart," Mathis said, drenched in sweat. "You have to go smart, not hard."
Will Mathis play like his old self when he does get on the field?
"I'm not Kreskin, Nostradamus. I don't know," Pagano said. "Time will tell. I'm not trying to be a jokester, but if anybody can do it, it'll be him."
If he does, the Colts' defense would get a big boost.
In 2013, Mathis accounted for nearly half of Indy's sacks (41). Without him last season, defensive coordinator Greg Manusky creatively generated enough of a pass rush to match that sacks total with an improved Erik Walden working on one side of the field and rookie Jonathan Newsome emerging as a pass-rushing threat late in the season.
Both are back this year and Indy has added Trent Cole at outside linebacker. Cole finished his career in Philadelphia ranked No. 2, behind Reggie White, on the Eagles' career sacks list.
Mathis believes he can be a major component in that mix, too,
"I'm making big strides, clearing a lot of hurdles," he said. "There's not much I can't do, it's more just being cautious."
Notes: As practice started, Grigson said he would address the contract of Pro Bowl receiver T.Y. Hilton at the appropriate time. Irsay had said Wednesday night that he intends to make re-signing Hilton and left tackle Anthony Castonzo as two of next season's top offseason priorities. ... Grigson also said he's been impressed with the hands displayed by speedy receiver Phillip Dorsett, Indy's first-round draft pick.