After a season marred by a suspension and injuries, Buffalo Bills Pro Bowl defender Marcell Dareus is looking to re-establish himself as one of the NFL’s premier defensive tackles.

“Tweaking’’ a hamstring, as coach Sean McDermott described it, on the second day of training camp wasn’t a good start for Dareus but after missing two days of practice, he was back on the field Tuesday at St. John Fisher College.

“We’ll monitor his reps as we work him back in,’’ McDermott said.

McDermott said he has been pleased with Dareus’ attitude, effort — and waistline. Dareus, who is listed at 331 pounds, arrived in Rochester looking to be in his best shape in years.

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“It’s been very positive. He’s done a great job,’’ said McDermott, who proceeded to mention a half dozen people working in the training and strength and conditioning areas who have worked with Dareus.

Dareus, who was slowed by a hamstring issue last season, said his leg was feeling “a lot better.’’

“Just going out there doing what I can, getting back into it,’’ he said after practice. “The trainers have done a great job, trying their best to get me out there as soon as possible.''

Dareus knows how important that is to silencing his doubters. He appeared in just eight games last season, tying a career-low with 39 tackles.

“If anything, I have something to prove to myself and to my teammates and the fans,’’ he said. “I just want to do my best. Me doing my best I know is good enough.’’

Dareus said he hasn’t incorporated any popular fitness programs involving yoga or pilates into his training but he does do a lot of cycling — and not just on a stationary bike. He owns about 20 high-end road bikes, he said, and will often do 10-mile rides.

“That’s my kind of thing, and hiking,’’ he said. “I like to hike trails and be in the woods.’’

Injury update: Aside from Dareus, cornerback Ron Darby returned to practice after missing time with a sore ankle.

Sitting out was running back LeSean McCoy, who was tackled by a stomach bug. Getting a veteran’s day of rest were center Eric Wood and linebacker Lorenzo Alexander.

The Bills return to the field at 8:45 a.m. Wednesday.

Game plan for Ragland: Second-year linebacker Reggie Ragland, who was expected to challenge Preston Brown for the starting middle linebacker spot, has yet to work with the first unit.

McDermott explained why, starting with the fact Ragland is essentially a rookie, having missed all last season with a torn ACL. The plan is to work him back slowly so that he can be an impact player for the long haul.

“Acclimating him to practice tempo — he missed most of the spring — acclimating him to the system and putting him in position, like we try to do with all of our players, to have success,’’ McDermott said. “I like what he did the other day, the second day in pads. I saw a physical aspect of his game, an emotional aspect of his game that we need in our defense. A lot of work remains for all of us, including Reggie at this point.’’

Ragland has worked with the second unit, in the nickel defense, and is a moving part with other players like veteran free agent Gerald Hodges at linebacker.

“I’ll do whatever the coach wants me to do,’’ he said. “If he wants me to sub, he wants me to sub. If not, I’m going to still play hard and come back there when I do my reps and stuff. But for the most part, I’m doing whatever coach wants me to do.’’

Rambo returns: Veteran safety Bacarri Rambo is out to prove what’s old is new again.

Rambo played two seasons for the Bills, appearing in 19 games over the 2014-15 seasons, before being waived and spending time last season with Miami.

Rambo was an impact player in his first Buffalo stint. He once intercepted two Aaron Rodgers passes in an upset Buffalo victory in December 2014. In November 2015 against the New York Jets, he forced two fumbles and had the game-clinching interception off ex-Bill Ryan Fitzpatrick.

“It’s emotional to get a phone call (from an NFL team) but to get one from Buffalo,’’ said Rambo, who re-signed with the Bills two days before camp began and was glad to hear his No. 30 was still available. “I love the fans here and I’m pretty well-known, so it was an emotional moment. My wife, in-laws and my parents, they were all very excited for me and just said, ‘God has a plan. Stick with the plan and continue to work hard.’ ‘’

With safety being a position of need, Rambo is already earning repetitions with the second unit.

“He obviously had skins on the wall, in terms of his experience and playing in this league and what it means, so that’s an advantage for us and for him,’’ McDermott said.

Pads are on: The Bills are running drills three-quarter speed, hitting but not tackling to the ground. There could be some full contact sessions on the horizon, though, perhaps Friday night when the Bills practice at New Era Field in Orchard Park when a big crowd is anticipated.

“We’ll take some opportunities to go live, when and how much remains to be seen,’’ McDermott confirmed. “We’ve got some ideas in mind. I’ve got it scripted out. That said, I’ve got to continue to keep the day-to-day pulse of the football team in mind in terms of where we are and what we need to get done yet. The overall health of the football team, too. So, I would like to turn it up a couple times before now and the first preseason game.’’

That game is Aug. 10 against the Vikings at home.

LROTH@Gannett.com

SiriusXM NFL hits camp

Former NFL executive Pat Kirwan and former quarterback Jim Miller will broadcast from Bills training camp at St. John Fisher College on Tuesday from 3 p.m. to 6 p.m. on SiriusXM NFL Radio.

The visit is part of Sirius' annual tour of NFL camps which runs through Aug. 21. The show is available nationwide on Channel 88 on satellite radio and on the Sirius app for subscribers.