Which Bills have most to gain in OTAs?

The shorts and flip-flops are out in Buffalo, which can only mean one thing: training camp is right around the corner.

While an exact date hasn't been announced, the Buffalo Bills will begin training camp as early as the third weekend in July. That's sooner than usual because the Bills will play in the Hall of Fame game in early August.

Even before the Bills kick things off at St. John Fisher College, players can get in valuable work over the next three weeks during organized team activities. While the emphasis is on teaching and installation -- not so much evaluation -- players who excel in OTAs could carry that momentum into training camp.

Obviously, it's beneficial for every player to attend OTAs, pick up the system quickly, and build a head of steam entering the summer. Yet for some Bills, it's even more important that they don't fall behind in the coming weeks.

In our view, here are the players who will be under the microscope the most in OTAs:

EJ Manuel: This is a no-brainer. Unlike Geno Smith, his 2013 draft counterpart in New York, Manuel won't face veteran competition during training camp. It's a move designed to take some pressure off Manuel, whose health and up-and-down rookie season have been well-documented. Yet it keeps the spotlight squarely on Manuel, as backups Thad Lewis and Jeff Tuel don't pose a challenge to supplant Manuel as the opening-day starter. How Manuel and Sammy Watkins, the Bills' 2014 first-round draft pick, fit together during the three weeks of OTAs will be of top concern from an outside perspective.

T.J. Graham: Graham could face an uphill battle during training camp this summer and will need to be sharper than most players over the next few months. He can't control how Mike Williams fares in training camp, or how Marquise Goodwin's role within the offense changes in his second season. Those two players are Graham's main competition. Goodwin is a near-lock to make the roster, while Williams' guaranteed salary makes him an unappealing cut come August. Yet if Graham can leap-frog either on the depth chart, it will help his case to stick. What Graham can control, then, is how he can become a more complete receiver. He's mainly a speed threat, but improving his pass-catching and route-running abilities should be his top goals.

Erik Pears: Pears turns 32 next month and while he proved durable last season with the Bills, his health and conditioning should be of prime concern as he preps for training camp. Pears faces stiff competition at right tackle from second-round pick Cyrus Kouandjio. Like Graham, Pears' fate could be out of his control. If Kouandjio develops well over the next few months, then I don't think the Bills will hesitate to make him their starter at right tackle. If Kouandjio is slower to come along, then Pears could hold onto his starting job. He struggled as a run-blocker last season and while OTAs don't involve contact, improving his technique should be tops on his list.

Marcell Dareus: The Bills exercised Dareus' fifth-year option for 2015 in April and within two weeks he was arrested for felony drug charges in Alabama. Dareus' court date hasn't been set yet and since he faces felony charges, the legal process could be drawn out. In the meantime, Dareus must make a good impression on the coaching staff if he participates in OTAs. He ended last season on the wrong note when he was suspended for parts of the final two games. OTAs are voluntary and the coaching staff can't discipline players for not taking part, but I can't imagine too many around the Bills' facility will be happy if any of Dareus' issues from last season carry over into OTAs or minicamp.

Duke Williams: The Bills want to give Williams a chance to make an impression and earn a starting role. As we've noted previously, Williams didn't take advantage of his opportunities last season. The Bills weren't able to re-sign Jairus Byrd and didn't sign any veteran to replace him. That leaves a gaping hole in the secondary. While the Bills signed Aaron Williams to a contract extension and praised him as their next young star, he will need to continue to prove it. Even then, who will start alongside Aaron Williams? Duke Williams has the chance to take over that spot but he'll need to take steps forward during OTAs, minicamp and training camp to lock down that role.