Nothing ever stays the same in the NFL. As soon as one player steps up his game, an established star starts to struggle. And we've targeted who those players will be for 2010.

ON THE RISE

Matthew Stafford, Lions QB
After an offseason of first-team reps as the emerging offensive leader, Stafford displayed “astounding” accuracy in training camp. The early preseason results are encouraging as well, with Stafford completing 72.4 percent of his passes.

Last year’s first overall pick has a much better handle on Scott Linehan’s offense this year. More importantly, he’s enjoying a dramatically improved supporting cast with a home-run hitting tailback (Jahvid Best), a seam-stretching tight end (Tony Scheffler), and a physical receiver (Nate Burleson) opposite the unstoppable Calvin Johnson.

Rashard Mendenhall, Steelers RB
The owner, head coach, and offensive captain all spent the offseason campaigning for a return to the Steelers’ blue-collar roots. With Ben Roethlisberger suspended four games, coordinator Bruce Arians is preparing to saddle up Mendenhall as his workhorse.

Arians has compared Mendenhall’s skills favorably to those of Marshall Faulk and Edgerrin James, two players he coached in Indy. One of only a half-dozen every-down backs in today’s NFL, Mendenhall is poised to enter the season as the Steelers’ offensive centerpiece.

Pierre Thomas, Saints RB
Reggie Bush has the name, but Thomas has the game. A legitimate argument can be made that he’s been the most effective per-play “starting” running back over the past two seasons in the Saints’ mix-and-match backfield attack.

Nobody runs the screen play better than Thomas, who excels at navigating the open field behind road-grading guards Carl Nicks and Jahri Evans. His 13.2 touches per game should rise considerably with Mike Bell now in Philly.

Jahvid Best, Lions RB
Coach Jim Schwartz saw Chris Johnson’s smashing debut with Titans up close and person as the defensive coordinator. He knew exactly what he was looking for when he targeted human highlight-reel Best as his new feature back.

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A big play waiting to happen, Best has been utilized heavily with the first-team offense early in exhibition action. The Lions haven’t spoon-fed him, and a more compact Best has excelled between the tackles, on the edge, and even in the passing game. His 4.3 speed will be accentuated on Ford Field’s turf, putting pressure on opposing defenses.

Arian Foster, Texans RB
Maurice Jones-Drew’s pick for a breakout player is a big back perfectly suited to Houston’s one-cut scheme. In one year this “229-pound beast as a runner, blocker, and receiver” has gone from undrafted free agent to unquestioned starter.

Coach Gary Kubiak hinted at an offseason epiphany from Foster, praising his newfound maturity and dedication in “becoming a hell of a football player.” With Steve Slaton sliding into a change of pace role, Foster is locked in as the lead back in one of the league’s most explosive offenses.

Mike Wallace, Steelers WR
The league-leader in yards per catch (19.4), Wallace enters his second season with lofty expectations. Hall of Famers Jerry Rice and Michael Irvin are two other receivers on the short list of rookies who averaged more than 18 yards per catch with more than 30 receptions.

Wallace spent the offseason working on his route running, and his impressive progress allowed the Steelers to deal Santonio Holmes without blinking. His ability to take the top off the defense with calls to mind Eagles’ Pro Bowler DeSean Jackson. Wallace could dethrone Hines Ward as Pittsburgh’s top receiver as soon as this year.

Johnny Knox, Bears WR
Knox’s 4.32 speed, change-of-direction, and leaping ability have drawn comparison to a young Torry Holt, the model for Mike Martz’s receivers. The offseason saw Knox emerge as the Bears’ best route runner and a perfect fit in Martz’ up-tempo offense.

By the time training camp rolled around, Knox had emerged as Jay Cutler’s favorite target. Showing easy separation in the first two preseason games, Knox is on his way to a 1,000-yard season as Martz’s featured offensive player.

Jabar Gaffney, Broncos WR
Looking down the barrel of age 30, Gaffney doesn’t fit the profile of a prototypical breakout. If we look deeper, though, the stars are aligned for a career year. Gaffney filled the Brandon Marshall role late last season, leading the NFL with 21 receptions for 282 yards in the final two games.

As the one Denver receiver most versed in Josh McDaniels’ offense, Gaffney is set to resume the go-to role with Marshall in Miami. The late-season flurry isn’t the first time he showed the ability to take over a game in McDaniels’ offense. He also averaged nine receptions for 104 yards in two Patriots playoff games back in 2007.

Jermichael Finley, Packers TE

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A matchup nightmare for opposing defenses, the freakishly athletic Finley abused Pro Bowl safety Adrian Wilson in last year’s NFC wild-card game with a franchise playoff record 159 receiving yards.

Perhaps no skill player in the NFL finished 2009 with as much promise as Finley, who led Green Bay in targets over the final eight weeks. He’s moved into the starting lineup this season, dramatically increasing his snap count. All of the signs are there for a dominant breakthrough campaign.

Zach Miller, Raiders TE
Here’s your dark-horse candidate to the lead NFL tight ends in catches and yards. Flying well below the national radar, Miller is one of only three tight ends to clear 750 yards in each of the past two years. What’s more, he did it with JaMarcus Russell throwing the ball.

Miller has been described as a "one-man wrecking crew" in Raiders camp, and he’s developed an early rapport with Jason Campbell. If his new quarterback remains as tight-end friendly as he was in Washington, Miller will join the ranks of the league’s elite.