PITTSBURGH -- Shamarko Thomas has gone from playing extensively as a third safety in the Pittsburgh Steelers' quarter defense to playing sparingly if at all aside from special teams.

All 16 snaps that Thomas logged in the Steelers’ 30-20 win against the Bengals last Sunday night came on special teams.

Thomas will likely finish his rookie season in a reduced role because of several factors, but the drop in playing time has left the fourth-round draft pick anything but discouraged.

“It’s part of the learning process,” Thomas said. “Next year I’m going to be more comfortable. Offseason I’m going to go real hard, bust my butt and come even harder.”

The Steelers will need him to do all of the above.

This could be the final season for both starting safeties unless Troy Polamalu agrees to a pay cut. Even if Polamalu comes back the Steelers still need to get younger at safety, something they deemed a top priority as far back as last April.

The Steelers traded a 2014 third-round pick to the Browns so they could add another fourth-round pick to draft Thomas, and it is pretty rare to see them make that kind of deal.

That is why Thomas' development during the offseason will be critical for a team that is facing a lot of turnover on defense.

“He’s going to hopefully be the future here,” reserve safety Will Allen said. “He’s explosive, has great instincts, and it’s about really helping him learn how to be a professional and play this game at a high level.”

Allen is a major reason why Thomas’ on-the-job training has been cut significantly.

Taking advantage of opening provided by an injury -- Thomas suffered a high-ankle sprain that sidelined him for two games last month -- Allen has played well as an extra safety, and his interception helped preserve the Steelers’ 37-27 win against the Lions on Nov. 17.

Allen has stayed on as the third safety, but he has also become another mentor to Thomas since re-signing with the Steelers in early October.

Allen, Polamalu and Ryan Clark have more than 30 years of NFL experience among them, and Thomas has tried to absorb everything he can from the trio.

“Will’s a great player, he’s been in the league for 10 years and I’ve got him, Ryan and Troy, so it’s a great learning process,” Thomas said. “I’m always trying to get in their ear, try to talk to them on the side. Everybody says rookies have to come in slow, but ... I feel like I did alright. I could have done better, made more plays on special teams, but you learn from it and get better next season.”