5 NFL Rookies Who Need a Great Training Camp to Replace Aging Veterans

Certain NFL training camps are set to feature intriguing battles between rookies and aging veterans. These particular first-year players will need strong camp showings to usurp experienced pros who may be getting up there in age but still have the ability to be credible starters.

The Chicago Bears will be hoping their top rookie can supplant a 31-year-old on the strongside of their front four. The Pittsburgh Steelers, meanwhile, will be counting on two mid-round picks to quickly prove themselves able to man key positions at the heart of their fearsome defense.

In Detroit, the Lions' veteran left offensive tackle will find his position under threat from a highly-touted rookie expected to start from day one. Meanwhile, the Denver Broncos may feel that their third-round pick provides a more diverse, big-play threat for a more expansive, Peyton Manning-led offense.

Here are the five rookies who need a great training camp to replace aging veterans.

Riley Reiff, OT, Detroit Lions

The Detroit Lions need first-round draft choice Riley Reiff to emerge as Matthew Stafford's blindside protector sooner rather than later. That means the rookie has to quickly beat out 12-year-veteran Jeff Backus.

Keeping Stafford upright is key to the Lions' hopes for success this season. Reiff is a better athlete on the edge than Backus. He has quicker footwork and is a technically gifted, big-bodied blocker.

The Lions need more agility at the position, in an NFC North division loaded with elite pass rushers Jared Allen, Julius Peppers and Clay Matthews.

Shea McClellin, DE, Chicago Bears

The Chicago Bears will expect Shea McClellin to waste no time forcing himself ahead of nine-year pro Israel Idonije. McClellin will be counted on to take some of the pressure away from Julius Peppers and provide a consistent pass rush on the strong side.

The former Boise State star plays with excellent leverage and tenacity. He will need to refine his repertoire on pass-rush moves and overcome any concerns about his lack of elite size.

Idonije has notched 13 sacks in the past two seasons, and the 6'6", 275-pounder has the size to overwhelm tight ends and be a force against the run. However, if McClellin can showcase more big-play potential in training camp, he should have no problem emerging as the day one starter.

Ronnie Hillman, RB, Denver Broncos

Third-round draft pick Ronnie Hillman could use a strong training camp performance to push for a starting spot ahead of Willis McGahee. Hillman is a more versatile backfield weapon, and that could give him the edge, as the Denver Broncos look to build an appropriate supporting cast for Peyton Manning.

The ex-San Diego State star is an excellent receiver and offers a greater breakaway threat than McGahee. The 10-year-veteran ran for 1,199 yards in 2011 as the fulcrum of a heavy run offense designed to maximize the rushing threat of Tim Tebow.

McGahee excels between the tackles, but the 30-year-old has taken a pounding in recent seasons and his smash mouth style may not be the ideal complement to Manning.

Alameda Ta'amu, NT, Pittsburgh Steelers

Alameda Ta'amu will need to impress legendary defensive guru Dick LeBeau at the Pittsburgh Steelers' training camp and prove he can replace stellar veteran Casey Hampton. Ta'amu has the size and aggression for the role, but Hampton has set the standard for 3-4 nose tackles and his importance to the Steelers' schemes will be tough to emulate.

At 6'3" and 348 pounds, Ta'amu fits the mold of the modern nose tackle. He is a stout force against the run and can certainly take on and hold up against double teams.

The Steelers are one of the few teams that still rely on a traditional, 2-gap 3-4, and they place a lot of pressure on the nose tackle position. With the 34-year-old Hampton attempting to come back from a serious ACL injury, Ta'amu can elevate himself to the starting job if he makes the most of training camp.

Sean Spence, LB, Pittsburgh Steelers

Sean Spence could use an exceptional training camp performance to make a case for replacing 32-year-old Larry Foote at the heart of the Pittsburgh Steelers' linebacking corps. The Steelers are looking to get younger on defense and pairing Spence with Lawrence Timmons at the inside of their 3-4 would be a positive step in that direction.

The 5'11", 231-pounder has the speed and instincts to be an effective sideline to sideline playmaker and and asset in underneath coverage. He is probably not big enough to rush from the outside and provide cover for James Harrison and LaMarr Woodley.

However, Spence could add some much-needed quickness and athleticism to the inside linebacker position.