Cardinals safety Tyvon Branch in action against the Raiders on Saturday.

David Johnson had a fantastic run during Monday's training camp practice, darting to his left and finding daylight for a gain of about 70 yards.

But he didn't score a touchdown, because Tyvon Branch chased him down from behind at the 16. The closing speed by the Cardinals' 30-year-old safety caught coach Bruce Arians off-guard, who figured his young superstar would win the foot-race.

"I think it surprised David, too," Arians said.

The Cardinals signed Branch in free agency last offseason, but he didn't make the impact expected as a pair of groin injuries shelved him for all but six games.

He took a paycut to stay with the team, and while Tyrann Mathieu, Antoine Bethea and Budda Baker are all bigger names within his position group, Branch has started at safety alongside Mathieu throughout training camp.

"Obviously you want to be on the field as much as you can, and you want to be in the best position you can to help the team win," Branch said. "That's the whole reason we play this game. Being able to go out there and compete every day, and for it to be working out the way it is, I'm obviously happy about that."

While a player like Baker may have the higher ceiling at this point in their careers, Branch is ahead mentally. Arians said Branch brings consistency to the secondary.

"He's very, very smart," Arians said. "Starting to get his hands on some balls."

Branch smiled when asked about also getting his hands on the hard-to-corral running back.

"I've still got a little speed," Branch said. "It ain't all gone. I had a tough offseason working hard. That's one of the things I worked on was getting my speed back and being able to run full tilt. Being able to showcase it against a guy like David, it makes you feel a little better. You see him run away from people all the time. Being able to catch him was cool."

JOHN BROWN UNCERTAIN OF FUTURE HEALTH

Wide receiver John Brown (quadriceps) continues to ramp up his activity at practice, but isn't yet at full strength.

He has been dogged by health issues dating back to last year's training camp, most notably a sickle-cell trait diagnosis. Brown said he's unsure if injuries will continue to be a nuisance moving forward.

"I'm just dealing with it the way it comes," Brown said. "I can't help what goes on. That's just the way my body is. I hope it will go away, but if it keeps coming, I just feel like I'll be a hurt to the team."

Fellow wideout Chad Williams (shin splints) did more work in practice on Tuesday while Aaron Dobson (hamstring) returned after a lengthy absence.

Left tackle D.J. Humphries (hamstring) returned for individual work, while linebacker Markus Golden (ankle), safety Rudy Ford (hamstring), linebacker Phillip Wheeler, defensive tackle Ed Stinson (hamstring), linebacker Jarvis Jones (back), wide receiver Brittan Golden (groin), tight end Ricky Seals-Jones (ankle) and wide receiver Carlton Agudosi (knee) didn't practice.

Quarterback Carson Palmer and linebacker Karlos Dansby received scheduled days off.

ARIANS FINE WITH SHORTENED PRESEASON

Commissioner Roger Goodell met with Arians Monday afternoon prior to his appearance at the team's fan forum, and the two discussed the length of the preseason.

Arians said a shorter exhibition slate wouldn't bother him. He believes the fourth game can help a rookie quarterback, but that work can also be done by practicing against another team during the week.

The Cardinals, for instance, had joint practices with the Chargers in San Diego last year during training camp.

"(A rookie quarterback) would play more in a two or three day practice against another team, seeing other coverages, than he would in that game anyway," said Arians, who had the scenario pop up as quarterbacks coach with the Colts when Andrew Luck was a rookie. "I think three (preseason games) is plenty."

DAVID JOHNSON KICKS OFF ANTI-BULLYING CAMPAIGN

Johnson met with 80 students from Phoenix and Glendale after practice to begin his "Run Thru Bullying" campaign. Johnson, who told the kids his own story of being bullied, will spend the next six-to-eight weeks raising awareness for the issue.