This is another in a series examining the Steelers' roster on a position-by-position basis as we count down the days to the opening of the team's 2015 training camp at Saint Vincent College.

WIDE RECEIVERS
When it comes to the Steelers' depth chart at the wide receiver position, there is a short-term view and a long-term view. The short-term view is to assess things in terms of who makes the 53-man roster because those are the decisions that have to be made first. The long-term view is to evaluate the competition among the wide receivers at camp and during the preseason in terms of how impactful the unit can become starting on Sept. 10 in Gillette Stadium.

With Antonio Brown, Markus Wheaton, and Martavis Bryant at the top of the depth chart, the Steelers' wide receivers can present a formidable challenge to any pass defense in the NFL. Brown's 129 catches last season represented the third-highest total in NFL history, Wheaton is an up-and-comer whose forte could end up being his run-after-catch ability, and Bryant is a guy who should get plenty of chances to benefit from Ben Roethlisberger's ability to throw a football a long way.

As a concession to the short-term view, that's three roster spots, with a fourth almost certainly to be allotted to rookie Sammie Coates. It took six weeks of regular season activity before Bryant convinced the coaching staff he was ready to play as a rookie, and Coates figures to need some seasoning as well.

"Right, we were hard on him," said wide receiver coach Richard Mann about Bryant's rookie season. "We held him out the first six or seven games because he wasn't ready. And when he was ready, we let him go. The same thing is happening with Sammie Coates now."

But Coates, the team's No. 3 pick from Auburn has too much of what NFL teams want in a receiver to get cut as a rookie. Just not a realistic scenario. And if he is able to stay on the practice field and continue the development he was showing during the offseason program …

"(Coates is) showing me he's a big kid who's got some speed," said Mann. "I think he might be tough, because I saw it on tape when I was watching college film. I also think he's smart enough to learn the offense. With that said, we will see when the pads are on."

So that makes four. The other spots on this depth chart – and the Steelers could keep as many as six receivers to open the regular season – will go to players with significant roles on special teams.

Darrius Heyward-Bey had a significant role on special teams last season, and he was re-signed during the offseason to a one-year deal. Shakim Phillips and Eli Rogers will get an opportunity to return kickoffs.

Also competing at the position will be C.J. Goodwin, who's intriguing because of his size – 6-foot-3, 190 pounds – and some playmaking ability he flashed during the offseason program; and dual-position guys Devin Gardner and Tyler Murphy. That's a total of 10 players competing for as many as six roster spots, with four of those already assumed to be taken.

Over the course of the 18 practices at Saint Vincent College that are open to the public, there will be a lot of interest paid to the battles for those roster spots, but the important work to be done by this unit during training camp and the preseason isn't all about separating the six to keep from the group of 10. It's more about how the top three, and then at some point later in the season, how the top four can help make the Steelers' offense into one of the dominant units in the NFL.

To that end, the ability to stay on the field and get the repetitions with Roethlisberger is going to be critical. Working on their craft, refining their roles within the offense, learning to utilize what they can bring to the whole to make it something special. That is what really will be worth watching.

"I have the guys from last year and they're stable," said Mann. "There are a lot of suspects with the new guys. We haven't gotten to tackling yet, and I'm old school. Right now, in shorts, they're just learning the offense and how to run plays. They will show what they have when the time comes to tackle. That's what I'm waiting on."

That competition Mann describes will determine who wins the battle. What happens in terms of the development at the top of the depth chart will help determine whether the Steelers can win the war.

TOMORROW: Tight ends