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.

CORNERBACKS
It's not to the same degree as Ben Roethlisberger, that's for sure, but the Steelers' success in 2015 definitely is tied to the performance they get from Cortez Allen. That's right. A fifth-year cornerback prospect is going to have a lot to say about whether the Steelers improve upon a season that included both an AFC North Division championship and a one-and-done in the playoffs.

"I think Cortez enters the (2015) season where he left off (in 2014)," said General Manager Kevin Colbert back in February at the NFL Scouting Combine. "We have to find out about Cortez and whether he can accept the challenge of being a starting NFL cornerback. He showed signs of that in the past. He was productive in spurts for us in the past. Again, you invest in players you think can be good players."

The Steelers invested in Allen last summer, and so far it has paid no dividends. After signing him to a five-year contract worth a reported $26 million, Allen started the season's first seven games and contributed two interceptions and eight passes defensed in them. But over the course of those starts, his play was in decline, and after getting benched following the win over the Houston Texans on Oct. 20, Allen would injure his thumb against Tennessee on Nov. 17 and land on the injured reserve list.

And so it will be that the Steelers will look "to find out about Cortez and whether he can accept the challenge of being a starting NFL cornerback" – quite possibly for the final time, one way or another – starting with this 2015 training camp.

"I think we have to look at it realistically, and say this is where he is, this is where we need him to be," said Colbert. "We are going to support him as he tries to get back to that spot."

There will be support, but one reality of the NFL is that fifth-year players are expected to produce, or else. The Steelers doubled-down on Allen when the team elected to pay him a $3 million roster bonus in the spring of this year.

"I'm here to support him, try to help him with his game, from technical to physical to mental, whatever I can do," said defensive backs coach Carnell Lake. "Hopefully, with diligent work every day, that will give him confidence to go out and play confident. Corners have to play with confidence. The only way you get confidence is to make plays and be consistent in practice."

As to the rest of the depth chart here, William Gay, who turned 30 on New Year's Day, is the senior member of the cornerbacks as well as the oldest starter on a defense that had seven thirtysomethings starting as recently as 2011 and six starting in 2012. Besides seniority, Gay also is a leader and the unit's best player. He has the longest consecutive games played streak among all NFL defensive backs at 128, and his three pick-sixes in 2014 set a franchise record.

Dependability and productivity are qualities the Steelers are looking to develop quickly in their two rookie draft picks – No. 2 Senquez Golson and No. 4 Doran Grant. During Coach Mike Tomlin's time collaborating on drafts with Colbert, the Steelers have had some success in using multiple draft picks on a position they are trying to strengthen quickly. When it worked best, it was linebackers in 2007 (Lawrence Timmons and LaMarr Woodley), receivers in 2010 (Emmanuel Sanders and Antonio Brown), and offensive linemen in 2012 (David DeCastro, Mike Adams, Kelvin Beachum). They're giving it another try with Golson and Grant.

Six cornerbacks were among the opening 53-man roster for the 2014 regular season, and the competition for spots should be fierce this summer even though Brice McCain, a nine-game starter, left for Miami in March as an unrestricted free agent.

Antwon Blake (pictured above) ended the 2014 season as the nickel back and recorded a key takeaway by recovering a fumble he forced in the division-clinching win in Cincinnati, but just as significant toward his case for a roster spot is what he is capable of contributing on special teams. He was tied for fourth with seven special teams tackles last season, and special teams is going to have a lot to do with who stays and who goes come cut-down day.

B.W. Webb came to the team as a waiver wire pickup before the 2014 season opened, and he was active for 10 regular season games, during which he contributed two special teams tackles. Kevin Fogg, who had already been waived by the Dolphins, was added to the practice squad in December and then signed to a futures contract on Jan. 5. Fogg reportedly ran a 4.49 in the 40-yard dash, had a vertical jump of 33 inches, and a broad jump of 10-4 inches prior to the 2014 draft, but there is a theory he needed more seasoning after playing for Liberty University of the Sun Belt Conference.

These are the seven cornerbacks on the Steelers' training camp roster right now. The team is going to need a couple of them to use their time at Saint Vincent College to show they deserve to be on an NFL roster, and the Steelers also are going to need one to show he can be a starter opposite William Gay.

TOMORROW: Safeties