Here are three to keep an eye on when the teams kick it off Sunday at 4:25 p.m. ET at the Edward Jones Dome.
Two years ago, Cardinals punt returner Peterson nearly beat the Rams by himself with multiple dynamic returns, including a “walk-off” return in overtime in the game in Arizona.
The Rams added Hekker before last season and the then-rookie did his part in helping to keep Peterson at bay. After two return touchdowns and an average of 27.8 yards per return in 2011, Peterson's numbers against the Rams fell to 15 yards per attempt last year.
Hekker helped neutralize Peterson through a combination of hang time and kicking toward the sideline. The concept is simple: Use the sideline as an extra defender, and get enough hang time to allow the coverage to get down the field.
In the first meeting against Peterson and the Cardinals, Hekker averaged 56.9 yards with a net of 46 on seven attempts, with three punts dropped inside the 20. That earned him NFC special teams player of the week honors.
An award won’t offer much comfort this time around, but Hekker acknowledged that it could at least help from a mental standpoint.
“The only thing it helps is as far as confidence,” Hekker said. “I think that’s something I’ll carry into this week and I’ll carry it kind of into this season. Having a whole year of experience. You can’t bank on last year’s success with a guy like that. They know that and we are all amped up and anxious to go. It’s going to be exciting.”
Cardinals defensive lineman Campbell has been a thorn in the Rams’ side seemingly for as long as he’s been in the league. The big, long-armed Campbell creates havoc with his pass-rushing skills and strength against the run.
Making matters more complicated are those Inspector Gadget arms, which add a 35.5-inch wingspan to his 6-foot-7 frame. In his past six games against the Rams, Campbell has 16 tackles, six sacks, three batted passes and a blocked field goal.
In defensive coordinator Todd Bowles’ new scheme, Campbell will work inside and out, but mostly lined up opposite starting Rams left tackle Long and expected starting guard Williams.
Campbell’s ability combined with those long arms makes him a tough matchup for either lineman.
“It helps him a great deal,” Long said. He’s very tall, strong, a great player. So you have just got to get into him, attack him and not let him lock his arms out and get away from you, because if that happens, he’s good with that.”
Of course, the easiest way to neutralize Campbell is to have him on the sideline. He was added to the injury report as questionable with a quadriceps injury suffered in Friday's practice. Campbell missed the second meeting between the teams last season with a calf ailment.
Because the Rams and Cardinals have been playing each other for so long, it’s easy to find a track record of the above matchups. This one, though, involves perhaps the league’s two most exciting rookie talents.
Austin and Mathieu are set to make their NFL debuts Sunday and will probably see plenty of each other, with Austin working in the slot for the Rams and Mathieu handling primary slot-corner duties for Arizona in nickel packages.
Obviously, the duo has yet to face each other in the NFL, but they did see each other back in a college matchup in 2011. Mathieu’s LSU team easily disposed of Austin’s West Virginia squad that day (47-21), but Austin had his way with the Tigers defense.
Austin finished that game with 11 catches for 187 yards, and though he wasn’t regularly matched up with Mathieu, he did get the better of the player then known as “Honey Badger” a few times.
Mathieu has impressed observers in Arizona nearly as much as Austin has done in St. Louis. They’ll probably see much more of each other Sunday, and the winner could strongly influence the game’s outcome.
“(He’s a) very instinctive, good player, plays way bigger than his size, got good coverage skills, good blitzer,” Rams offensive coordinator Brian Schottenheimer said of Mathieu. “(He’s a) good football player, real good football player. He and Tavon have had some battles in the past. It’ll be fun to watch them go at it.”