The first piece of 2016 roster-building business was a significant one: Locking up emerging tight end Zach Ertz to keep a piece of their young core in place, with much more work to be done.

Keeping Ertz, now signed through 2021, was a no-brainer after seeing him take the next step in his upward-trending career. Ertz caught 75 passes in 2015, had a final month unlike any tight end in NFL history -- 35 receptions and 450 receiving yards -- and is deservedly mentioned among the best at his position. Ertz is young, rising and a tireless worker. He's a Philadelphia Eagle, hopefully, for the rest of his career.

And Ertz is a piece around whom the Eagles can build. After putting the coaching staff in order over the course of the last couple of weeks, the Eagles are now hard at work on the roster and the salary cap and trying to get a long-range success plan in order. If there is a similarity to what the organization did in the early 2000s -- draft well, develop the players and keep as many as possible for as long as possible -- it's a winning formula.

Ertz joins players like center Jason Kelce, running back DeMarco Murray, linebacker Mychal Kendricks, cornerback Byron Maxwell, defensive end Brandon Graham and linebacker Connor Barwin as long-term Eagles, as core players. Certainly, every one of those players must step up his game from a year ago, when the 7-9 Eagles missed the playoffs and, truthfully, not a single player on the roster could say what he did was enough. So, too, are the younger Eagles the team is counting on to mature -- like wide receivers Ronald Darby, Josh Huff and Nelson Agholor and cornerback Eric Rowe and linebackers Jordan Hicks and Kiko Alonso and, well, who knows who steps up and thrives in these new schemes with these new coaches?

The goal is to build a deep, robust roster that develops continuity and wins as a group for a large handful of years. There are probably more players on the Eagles' wish list. You'd think defensive lineman Fletcher Cox is someone the Eagles want to keep for seasons to come (he is scheduled to be an unrestricted free agent after the 2016 year). Same with right tackle Lane Johnson (whose rights the Eagles control through the 2017 campaign) and defensive lineman Bennie Logan (scheduled to be an unrestricted free agent after the 2017 season).

Then you look at what could be a tricky free-agency period starting in March. Here are the Eagles scheduled to be unrestricted free agents: quarterbacks Sam Bradford and Thad Lewis, wide receiver Seyi Ajirotutu, defensive end Vinny Curry, defensive tackle Cedric Thornton, linebacker Najee Goode, cornerbacks Nolan Carroll and E.J. Biggers and safety Walter Thurmond. How can you predict which of those players returns?

There is some business to clean up after last March's free-agency activity, when the Eagles traded for Bradford's one-year contract and signed big deals with Murray and Maxwell. The Eagles also need to get back to some roster stability after the upheaval of the last two offseasons. Only 21 players on the active roster at the end of the 2015 campaign played with the Eagles in that playoff loss to New Orleans in the 2013 season -- Rick Lovato, Brent Celek, Jason Peters, Brandon Graham, Riley Cooper, Kelce, Thornton, DeMeco Ryans, Cox, Kendricks, Curry, Dennis Kelly, Allen Barbre, Barwin, Donnie Jones, Johnson, Ertz, Logan, Matt Tobin, Brandon Bair and Goode.

That's just too much change. It's time to get back to some stability.

Signing Ertz is a strong first step. He's going to be a featured piece in Doug Pederson's offense, no doubt about that. Pederson helped Travis Kelce become a Pro Bowl tight end in Kansas City, moving him around the formation to create favorable matchups, and he's going to do the same here.

"I would like to do that," Ertz said on Monday. "I'm excited to see what this offense can accomplish. I just want to be part of it and do whatever the coaches want me to do."

This is the kind of move that screams "big picture," and that's exactly the intention. The Eagles aren't going to rush into anything here. They know they have a lot of work to do to get the roster where it needs to be. The team to beat in the NFC is Carolina, which lost just one game all year and heads to the second Super Bowl in its franchise history. The key pieces in Carolina have been in place for years -- Ron Rivera became the head coach in 2011, taking over a 2-14 team, and promptly made quarterback Cam Newton the first overall pick in that draft. Newton has played and started in all but two games since then, and he is clearly the odds-on favorite to win the NFL's Most Valuable Player Award.

The head coach and the quarterback ...

A lot of tough decisions are to be made in the weeks ahead for the Eagles. They have to get order restored, stability regained. Signing Ertz was the right first move. More is coming, in whatever form it may be. Closing the gap and catching Carolina is going to take a lot of the right kind of moves like the one the Eagles made on Monday locking up a rising star at tight end through 2021.