5 Eagles who must thrive

1. Casey Matthews Linebacker

6-foot-1, 231 lbs. Rookie, 4th round

Why: Handing the keys — and headset — of the defense to an untested rookie is a bold move, especially on a unit with at least six new starters. We know Matthews possesses the pedigree — well-documented, by now — but he was often gobbled up by blockers in the preseason. Jim Washburn’s “wide-nine” technique will put the onus on Matthews to stop teams from the dink-and-dunk.

2. Rodgers-Cromartie Cornerback

6-2, 182 lbs. 4th NFL season

Why: The challenge here is to simply get DRC on the field — in some capacity. He is the quickest of the Eagles’ trio of cornerbacks and flashed his athleticism by blocking a field goal two weeks ago. He and Nnamdi Asomugha were often swapped in the slot on nickel looks, which seemed to confuse the opposition. Rodgers-Cromartie has the potential to be a game-changer, but he’ll have to take advantage of snaps.

3. Todd Herremans Right tackle

6-6, 321 lbs. 7th NFL season

Why: It isn’t a given that Herremans will succeed here. He hasn’t played much tackle since college, but the coaching staff is banking on his high football IQ and supreme athleticism. Besides, they were out of options with the injury to Ryan Harris and sloppy play of King Dunlap, and they desperately needed a steady vet to protect Mike Vick’s $100 million blind side.

4. Juqua Parker Defensive end

6-2, 250 lbs. 11th NFL season

Why: The oldest Eagle stands to benefit the most from the team’s free agent spending spree. Remember, the 33-year-old reeled off four sacks in the first three weeks last season before hitting the wall. Of course, that has been his MO in recent years. Since 2007, Parker has 24 sacks, but 19 of those have come on or before Nov. 15. There are plenty of snaps to go around in Juan Castillo’s scheme, with its frequent shuffling of defensive ends, and that should keep the elder statesman fresh.