And then there were four. That's it. Only four players remain on the Steelers roster who are the proud owners of two Steelers Super Bowl rings – James Harrison, Heath Miller, Ben Roethlisberger, and Greg Warren, all who were part of the Super Bowl XL and XLIII championship teams.

"That two ring group is getting real small," said Harrison. "It's a young man's game. You can't play it forever. You have to be grateful for the time that you get and move on from there."

Gone from that era of two Super Bowl rings are Troy Polamalu and Ike Taylor, who both retired this offseason, and Brett Keisel who was released. It's a new look, a younger look, but one Harrison said you just have to adjust to. 

"It will be a little different, but that is part of the game," said Harrison, who came out of a short retirement to play in 2014. "It's unfortunate to see them go, but I am grateful I had them here that long and watched them play and played with them. It's a young man's game. When it's time to go you have to be ready to make that transition."

Harrison said that each year there are changes to the makeup of the defense and the team overall, and this year is no different.

"Each year is a new era because you have a new set of guys," said Harrison. "No defense comes in with the same group of guys year in and year out from every position. I think each year is a new group, new era."