Eagles have hands full covering Lions' Calvin Johnson

At the beginning of each week, Eagles cornerback Dominique Rodgers-Cromartie takes the scouting report compiled for the Eagles defense and follows a routine. He checks opposing wide receivers' speed, listed by 40-yard-dash time. He then sees how many passes have been thrown in each receiver's direction.

When Rodgers-Cromartie started this exercise while preparing for the Detroit Lions, he noticed Pro Bowl receiver Calvin Johnson's time for the 40 was 4.38 seconds. Every other receiver was slower than 4.5 seconds. The targeted attempts were telling, too - an average of 10.75 in four games for Johnson, including 12 in each of the last three games. It was also worth noting Johnson's height and weight - 6-foot-5 and 236 pounds, taller and heavier than any Eagles cornerback.

It was easy for Rodgers-Cromartie to come to a simple conclusion: "He's got it all."

Defending Johnson - a task that likely will include double coverage - requires considerable thought, but there are few answers. Eagles coach Andy Reid joked that Johnson earned the nickname "Megatron" for a reason. The Eagles take pride in their starting cornerbacks, and Rodgers-Cromartie and Nnamdi Asomugha have both earned Pro Bowl appearances.

"From the past, I saw a lot of the press guys," Johnson said. "They try to slow you down off the ball a little bit. It's a tough call, because [the Eagles] have two good ones."

Yet the Eagles struggled to stop the Arizona Cardinals' Larry Fitzgerald, another standout receiver they encountered this season. The team changed its strategy from shadowing Fitzgerald with one cornerback to keeping Asomugha and Rodgers-Cromartie on their respective sides, and Brandon Boykin in the slot. Fitzgerald finished with nine catches for 114 yards and a touchdown in an Eagles loss.

"Whatever we didn't do against Larry," Asomugha said, "I think we've learned from that."

If the Eagles decide to shadow Johnson, it's reasonable to wonder whether the task would go to Rodgers-Cromartie or Asomugha. Rodgers-Cromartie stayed with Steelers receiver Mike Wallace last week and typically is assigned to speedy receivers. Asomugha is especially strong at playing press coverage at the line of scrimmage, so he could theoretically defend bigger receivers.

Asomugha has been targeted 22 times this season and has allowed 12 catches for 179 yards and a touchdown, according to Pro Football Focus. Rodgers-Cromartie has been targeted 27 times and has allowed 12 catches for 174 yards, and also grabbed three interceptions.

"Sometimes, it just depends on where Nnamdi is or whether we're matching receivers," defensive coordinator Juan Castillo said. "Sometimes, we're putting Nnam on the guy that they're throwing more balls to, and sometimes we put Dominique over there."

When the Eagles signed Asomugha to a $60 million contract in 2011, he was billed as an elite shutdown cornerback. This week's game against Johnson was the type of matchup that put him in such high demand.

"It's what I've done throughout my career," Asomugha said.

Asomugha now endures questions about whether he is still that type of player. He was never targeted more than 30 times in his final three seasons with the Oakland Raiders, and he's already near that total this season. Quarterbacks amassed a 96.6 passer rating against him in the first five games.

"That's not even close," Asomugha said of whether he's targeted more. "But it's a completely different scheme. And regardless of that, that's a beautiful challenge. You want opportunities to play as opposed to just being out there."

When Asomugha thrived in Oakland, he was particularly adept at using the sideline to his advantage - "like another defender," he said. The scheme in Philadelphia requires different responsibilities and seldom includes a single safety over the top. Looking at the targets now compared to his time in Oakland would be an inexact examination of how he's playing.

"There's not really a statistical measure," Asomugha said. "There's so much that goes into it. You're looking at yourself, you're looking at what your responsibility was on that play. And then a lot of times, it can look like that responsibility was you, but you know it wasn't, so you grade it differently."

Rodgers-Cromartie has thrived this season upon returning to outside cornerback, where his speed, size, and natural ball skills offer a template for one of the game's best corners.

Only two cornerbacks are limiting quarterbacks to a lower passer rating on balls thrown to their side this season, according to Pro Football Focus, and the percentage of balls that an opposing receiver catches on him is the eighth lowest in the NFL.

That's why the question of whether it's Asomugha or Rodgers-Cromartie - or both - covering Johnson is so compelling. The Eagles have shadowed receivers and kept their cornerbacks on designated sides this season. They can also mix elements of both plans. What's certain is they must have a better strategy than they did against Fitzgerald.

"I don't want to give away what we're going to do," Castillo said. "Hopefully we can talk about it after the game, and you can say, 'Juan, that was a good game plan that you all had.' "

Jim Schwartz is in his fourth season as the Lions coach, so he has seen enough to know that every opposing game plan is built around stopping Johnson. Few accomplish that task.

"People play box-and-one on him, to use a basketball term," Schwartz said. "They double him and cheat somewhere else."

Because of Johnson's size and speed, there is not a prototypical cornerback to cover him. The best chance is slowing him at the line of scrimmage, which requires a cornerback strong in press coverage. That is supposed to be one of Asomugha's best skills, although Rodgers-Cromartie has covered Johnson in the past, too.

"The guys that are 4.5-plus, I tend to say in my head, I'm going to beat you with my feet," Rodgers-Cromartie said. "Against a guy like Calvin Johnson, I'll try to disrupt him. I'll try to slow him down, disrupt him, not try to let him get going."

The Lions try to prevent double teams by moving Johnson into the slot. It has been a three-year development for him, transforming from strictly an outside receiver to one who is both a deep threat and a middle-of-the-field option.

Because slot receivers are smaller and quicker, opposing cornerbacks - such as Boykin, who is 5-foot-9 - are often similarly built. That makes Johnson a mismatch and forces defenses to adjust. The Eagles used Boykin on Fitzgerald and New York's Victor Cruz to mixed results, so they might need to play Asomugha in the slot when Johnson moves inside. Rodgers-Cromartie struggles when he needs to move inside.

Asomugha, Rodgers-Cromartie, and Boykin all studied Johnson. Cornerbacks search for tendencies to see what routes if any a wide receiver likes to run, or how he makes certain breaks. But some characteristics override any tendencies, and those are the first ones Rodgers-Cromartie saw on the scouting report: Johnson is fast, he's big, and the ball will be thrown in his direction.

"Only tendency you can get on them, guys like Calvin Johnson and Fitzgerald, is they're going to get the ball," Rodgers-Cromartie said. "You know it's going, no matter what situation it's in."