JACKSONVILLE – Today's look at the Jaguars covers familiar ground.

That's not easy, because when you look around the Jaguars' roster as 2014 Training Camp approaches, what strikes you is that it's difficult finding much that's not relatively new.

The Jaguars since Head Coach Gus Bradley and General Manager David Caldwell took over in the 2013 offseason have steadily and quickly revamped the roster to such an extent that finding veterans with extended tenure is challenging.

It's also increasingly difficult to find players who predate Caldwell and Bradley.

Of the 90 players on the roster, just 18 were acquired before Caldwell and Bradley arrived, and only three – defensive end Tyson Alualu, tight end Marcedes Lewis, kicker Josh Scobee – have been with the team four or more seasons.

This is a changing locker room, a changing culture and a changing roster. That's not surprising for a young team in Year Two of a building process, and it's equally unsurprising that the main storylines of this team in training camp will be about how new faces fit into and contribute in new places. 

At the same time, there are veterans who will be key and several mainstays – i.e., players who predate the arrival of Caldwell and Bradley— who must play well.

Here's a look at five such players:

1) Paul Posluszny, middle linebacker.This is an easy choice for this list, because if any player on the Jaguars' defense – or on the entire team for that matter – has been a reliable, productive mainstay in recent seasons, it's Poslusnzy. He's perhaps the team's best free-agent signing of the last decade, joining the team just before 2011 training camp. He not only made his first Pro Bowl last season, he did it in a time of transition in which the entire defense was changing around him. Because Red Bryant is expected to start over Tyson Alualu at one defensive end, Posluszny when the season opens likely will be the only player on defense who has started since the 2011 season. He remains a key leader and model of consistency on defense.

2) Cecil Shorts III, wide receiver.Though Shorts has been a mainstay in recent seasons, the Jaguars need him to be even more of one this season. A fourth-year veteran, Shorts has shown signs the last two seasons of developing into one of the league's more productive receivers, but overall offensive struggles and injuries have kept him from reaching the level he wants. With Justin Blackmon suspended indefinitely, Shorts is easily the most experienced receiver on a very talented – but very young – wide receiver corps. Shorts in 2012 flirted with becoming the first Jaguars receiver to reach 1,000 yards in a season since Jimmy Smith in 2005. If he stays healthy this season, he might do more than flirt with that plateau.

3) Josh Scobee, kicker.Did we say Posluszny was the biggest mainstay? If you include special teams, that title might go to Scobee. A fifth-round selection in the 2004 NFL Draft, Scobee is now entering his 11th NFL season, but he may be kicking at the highest level of his career. He has converted 71 of 78 field goals over the last three seasons, including 23 of 25 last season. He has at times in recent seasons been the Jaguars' most productive offensive player. The team would like for that to not be quite as true this season, but Scobee's reliability and ability in the clutch still make him key.

4) Tyson Alualu, defensive end. The fourth-year veteran may be slightly less of a mainstay than in the past because he likely won't be starting this season. But that doesn't mean the former first-round selection in the 2010 NFL Draft isn't important. He's expected to back up Red Bryant at the five-technique defensive end position. But while he won't be starting, but the Jaguars signed players such as Bryant, end Chris Clemons and tackle Ziggy Hood because they wanted a heavy rotation on the defensive line; Alualu should be a part of that. Alualu is a solid fit for the run-defense oriented five-technique, and he has yet to miss a game in four NFL seasons.

5) Marcedes Lewis, tight end.Lewis could be more than a mainstay; the nine-year veteran could have a chance at another "breakout" season. Lewis, a first-round selection in the 2006 NFL Draft, is by four seasons the Jaguars' most-tenured position player. He also remains one of the best blocking tight ends in the NFL, and remains a player for whom defenses must account. That makes him valuable to the offense no matter his receiving numbers, but there's a feeling that his productivity in the passing game could increase this season. Offensive coordinator Jedd Fisch believes Lewis' skill set fits the Jaguars' offense perfectly and though he caught just 25 passes for 359 yards and four touchdowns in 11 games last season, Fisch said during the offseason those numbers could have been much bigger had Lewis been healthy. With the improvements around Lewis this season, he could be a far bigger part of the passing offense and could have one his better NFL seasons.