Rare was the time a Steelers rookie defender ever got onto the field. They'd work their way up, usually behind a cadre of experienced and talented veterans and, perhaps, if they were worthy of it, maybe got a dozen snaps per game.
Mix in one part injuries, one part talent and one part overhauled roster, and suddenly, as of Monday, five Steelers' rookies will have had starts for the defense since Week 2 of last season.
Jarvis Jones replaced Jason Worilds for a spell in the Steelers' starting lineup at right outside linebacker in 2013. Vince Williams got the start for an injured Larry Foote in Week 2 as well. Both started the majority of the season. Ryan Shazier was an even rarer Week 1 starter as a rookie in 2014 and, due to a shoulder injury to Steve McLendon before a Week 7 game against Houston, second-round pick Stephon Tuitt got the starting nod at defensive end, as Cam Thomas shifted over to nose tackle.
Now, due to another McLendon shoulder injury, Dan McCullers will make his first NFL start on Monday Night Football against Tennessee in Week 11. He'll play nose tackle, with Thomas likely remaining at end, and Tuitt waiting in the wings.
McCullers wouldn't be starting if not for McLendon's injury, and it's important to remember that distinction. While optimism should be high for the Tennessee Shade Tree, this is strictly a spot-start; he didn't win the spot outright the way Shazier did this year or Jones did last year. Incidentally, he joins Williams as the team's last two sixth-round picks who became starters via injury their rookie year.
Jones and Shazier are the team's last two first-round picks.
Rookie second-round pick Stephon Tuitt can't be considered very far from a promotion, either. While veteran starter Cam Thomas has improved since a rough start to the season, it's only a matter of time until Tuitt assumes a starting position on this defense. Williams will continue to rotate snaps with Sean Spence at inside linebacker until Shazier returns from an ankle injury that has cost him the last two games (he already has been ruled out against Tennessee). Even upon his return, it's likely the trio will continue to be used based on weekly matchups, with none of them likely to get the vast majority of snaps overall.
It's all part of a reformation on the defensive side the ball. The Steelers have been undergoing this transition since last season, and they could see a vast change in their level of experience on the field in 2015. McLendon would count for $2.8 million against the Steelers' 2015 salary cap, the last year of a three-year deal he signed before the 2013 season. For argument's sake, if the team decides to move on from McLendon and start McCullers, it's highly likely Tuitt will be starting opposite Cam Heyward, giving the Steelers two second-year players on their defensive line. Jones has missed the majority of this season with a wrist injury (he's on IR-Recall, and is now eligible to practice, but hasn't done so yet), but if he and Shazier are healthy, they'd be the starters in 2015.
The team also has a decision to make with Troy Polamalu, as Shamarko Thomas is waiting in the wings. The cornerback position is wide open for 2015 as well.
Certain moves could be made which would all but remove every 2012 Steelers' defensive starter, with the exception of Lawrence Timmons, from the field. Most teams go through this level of turnover but perhaps not on such a truncated schedule.
McCullers' start is the result of injury, but other player moves the Steelers make moving forward may not be injury-related.