Buffalo Bills general manager Brandon Beane's stance on rookie quarterback Josh Allen has been clear: He will start No. 3 on the depth chart but will have a shot to earn the starting job this summer.

How the Bills divide first-team reps in training camp and split playing time in the preseason between Allen and veterans AJ McCarron and Nathan Peterman remains to be seen. For now, McCarron's experience seems to give him the edge to begin the regular season as the starter.

But if Allen wins the job or gets a chance to start at some point during the season, one potential stumbling block for the No. 7 overall pick will be his supporting cast.

If QB Josh Allen (17) wins the Bills' starting job, he could be targeting fellow rookies Ray-Ray McCloud (3) and Austin Proehl (87). Jeffrey T. Barnes/AP Photo

No matter who plays quarterback, the Bills' offense is likely to run through running back LeSean McCoy for a fourth consecutive season. McCoy, who turns 30 in July, has seen his workload increase since being traded to Buffalo in 2015. He might cede some carries this season to free-agent addition Chris Ivory, but McCoy still figures to be the centerpiece of the offense.

Beyond McCoy, Allen is surrounded with more questions than answers, starting with his offensive line.

The Bills seem to have found their left tackle of the future in 2017 second-round pick Dion Dawkins, who started 11 games in place of an injured Cordy Glenn last season. His presence largely mitigates the loss of Glenn in a pre-draft trade to the Cincinnati Bengals that gave the Bills the No. 12 overall pick, which they used in the deal to trade up for Allen.

However, the retirements of center Eric Wood and guard Richie Incognito this offseason leave the interior of the Bills' offensive line in a state of uncertainty. The Week 1 starters at guard and center figure to draw from a group that includes Ryan Groy, Russell Bodine, Vladimir Ducasse and John Miller -- and perhaps 2018 fifth-round pick Wyatt Teller -- but there likely will be at least an initial drop-off from the Pro Bowl-caliber play the Bills received from Incognito and from Wood's leadership at the line of scrimmage.

In addition to Allen beginning his NFL career behind what has the potential to be a shaky offensive line, the first-round pick also must contend with a group of wide receivers that is trying to shake off a terrible 2017 season.

Collectively, Bills wide receivers last season caught 115 passes (worst since the 2011 Baltimore Ravens) for 1,474 yards (worst since the 2011 Jacksonville Jaguars). From that group, the Bills allowed Deonte Thompson (27 catches for 430 yards last season) to leave in free agency to the Dallas Cowboys and Jordan Matthews (25 catches for 282 yards) to sign with the New England Patriots.

Which wide receivers are left for Allen -- if he wins the job -- to throw to this season? Here is a rundown:

Kelvin Benjamin: Beane was part of a Carolina Panthers front office that drafted Benjamin in 2014, and the Bills' GM felt strongly about Benjamin after dealing third- and seventh-round picks to acquire him at the trade deadline last October. At the time, Beane touted Benjamin's size (6-foot-5) and catch radius, saying a quarterback could throw the ball in Benjamin's general direction and he would make contested catches. Perhaps that quality could benefit Allen, whose accuracy was questioned in college at Wyoming. The key for Benjamin will be staying healthy, as he dealt with early-season knee issues last season with the Panthers and later tore his right meniscus shortly after joining the Bills. Given the Bills' questions at quarterback, it is far from an ideal situation for Benjamin to take advantage of a contract year and earn the kind of deal that many of his 2014 draft counterparts have received.

Kelvin Benjamin is entering a contract year and will aim for a big season after making 48 catches in 14 games last year with the Panthers and Bills. Icon Sportswire

Zay Jones: An arrest in March was probably more embarrassing to Jones than it was detrimental to his ability to perform this season. Beane and Bills coach Sean McDermott have seemingly put the episode with Jones behind them and want the 2017 second-round pick to focus on improvement after what he considered a "humbling" rookie season. His production last season -- 27 catches for 316 yards and two touchdowns -- makes him perhaps the NFL's worst No. 2 receiver entering 2018. He has the talent to be better than that, but he must show it.

Jeremy Kerley: Signed in April, long after the start of free agency, Kerley fits the traditional physical profile of what Buffalo could use in its slot receiver, which it has lacked in recent seasons. He is 5-foot-9 and 188 pounds, and he possesses some short-area quickness. The best-case scenario for the Bills is Kerley puts his 2017 season, which included a foot injury and an NFL suspension, behind him and can match his career-high production (64 catches for 667 yards and three touchdowns) from 2016. The worst-case scenario is that he looks like a 29-year-old receiver playing for his third team in three seasons and fails to stand out in training camp as he attempts to earn a 53-man roster spot.

Andre Holmes and Rod Streater: While Kerley's experience makes him the most likely player at the moment to earn the role as the No. 3 receiver, the Bills have a pair of other veterans on their roster who could make a push. Holmes, 29, contributed mostly on special teams last season and is four years removed from catching a career-high 47 passes in 2014. Streater, 30, flashed in the preseason last summer but is five years removed from having a career-high 60 catches in 2013. Both are taller receivers who would bring a different dimension to the No. 3 receiver role than Kerley. However, there is little statistical evidence in recent years to suggest either would be productive.

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Ray-Ray McCloud and Austin Proehl: The Bills' sixth- and seventh-round picks in 2018 could take advantage of the Bills' depth issues at wide receiver and win roster spots this summer. McCloud's best path is probably as a returner, while Proehl -- like his father, Ricky -- is a natural fit as a slot receiver. As draft selections, the Bills could be inclined to keep them over comparable options.

Kaelin Clay and Brandon Reilly: The Bills re-signed Clay, whom they acquired in a trade last September and later waived in October. He has six career catches since entering the NFL in 2015, so at best he is a peripheral option. Reilly, an undrafted free agent last season, caught the eye of fans by catching 11 passes for 139 yards and a touchdown last preseason. But he spent most of the season on the practice squad and did not play after being promoted to the 53-man roster in Week 14, so there is little basis on which to expect Reilly to become a contributor to the offense in 2018.

How could the Bills improve their depth at wide receiver? The highest-profile receiver on the free-agent market remains Dez Bryant. Beane said in his post-draft news conference on April 28 that the Bills evaluated Bryant on tape after the Cowboys cut him on April 13.

"Dez is a very good player," Beane told WGR 550 on April 30. "Is he the same player he was five years ago? Probably not. But he can still play in this league and can help a team. I’ve never personally met Dez. We would have to bring him in and visit with him and see if he’s a fit. We were generally focused on what we wanted to get in the draft before, looking at that. It’s probably something we’ll look at, but that’s all I can say for right now."

Beane also has noted that more players could become available before the start of the regular season.

"It's a 12-month process to build this roster," he said at the owners meetings March 27. "We have to make sure we have the team the way we want it [in September]. There's always an anxiety, sometimes from people in our own building, like, 'Hey, we got to get this, we got to get this.' There are plenty of times where guys come available after the draft, in June. We saw it last year at receiver with [Jeremy] Maclin and [Eric] Decker.

"So we still got a lot of time."