Cardinals running back David Johnson (left) with Rams running back Todd Gurley after their game in St. Louis last season.

David Johnson and Todd Gurley were saddled with different expectations as they trained together for the NFL Scouting combine early in 2015.

One was a small-school sleeper pegged for the middle rounds of the draft. The other was a college superstar earmarked for stardom.

But as they hung out at their hotel in Pensacola, Florida each night, they made a pact. In the lead-up to the draft, there was constant chatter about the devaluing of their position, as no running back had been selected in the first round of the two previous drafts.

"That's what we were hearing, all the way up until the draft," Johnson said. "With our class, we kind of wanted to bring running backs back into the focal point of the NFL."

As the pair prepares to square off more than a year-and-a-half later, both are making good on that deal.

Gurley, who broke the first-round-less streak when he was taken No. 10 overall by the Rams, is the reigning Offensive Rookie of the Year after accumulating 1,106 rushing yards and 10 touchdowns a season ago. He's averaging only 2.9 yards-per-carry this season but is already the focal point of the Los Angeles offense.

Johnson, the Cardinals' third-round pick, was dynamic down the stretch last season and has been the best player on offense in 2016. He has rushed 47 times for 217 yards and three touchdowns while adding 10 receptions for 169 yards in three games.

The 2015 running back class features other early contributors like Melvin Gordon, Ameer Abdullah, Duke Johnson, Tevin Coleman, Matt Jones and Jeremy Langford.

As NFC West foes, Johnson and Gurley see each other after games twice a year. Most of the conversation is about family, but the pact is not forgotten.

"We're always talking to each other, telling each other, 'Keep putting on for the draft class,'" Johnson said.

NO DOUBTING TOUGHNESS OF MATHIS

Right guard Evan Mathis practiced in full on Friday and will play against the Rams. It's a quick return after sitting last week with a turf toe injury, and it's the second potentially significant injury he's bounced back from this season.

Mathis suffered an ankle sprain in the opener which was expected to sideline him between a week and a month, and he played the next game against the Buccaneers. It shocked teammates who saw a black-and-blue foot early in the week.

"Thursday of that week, the trainers asked me if I wanted to go walk in the pool," Mathis said. "I said, 'Let's try to run on the field and see what it feels like.' After I was out there for a little bit, I said, '(expletive) it, let's go practice.'"

Turf toe injuries can often linger, but Mathis was given full-go status on the Friday injury report, and his return is important against the stout defensive front of the Rams.

"He's pretty damn tough," Arians said. "Two weeks out of three he sucked it up, got out there and wants to be with his teammates."

DREW BUTLER WILL MISS RAMS GAME

Punter Drew Butler (calf) didn't practice this week and will miss Sunday's game. New addition Ryan Quigley will punt and be the holder on field goals. Arians said Monday his preference was to keep Butler active as the holder, but he's in a walking boot and not physically capable. Defensive tackle Frostee Rucker (knee) has also been ruled out.

Safety Tyvon Branch (groin), linebacker Kareem Martin (knee) and cornerback Justin Bethel (foot) are listed as questionable.

For the Rams, defensive end William Hayes (ankle) is doubtful, while wideout Tavon Austin (shoulder), wideout Kenny Britt (thigh), defensive tackle Dominique Easley (illness) and cornerback Lamarcus Joyner (toe) are questionable.