Hightower has moved into the backup role, and he's playing in short yardage and goal line situations. He appears faster than advertised. The fifth-round pick out of Richmond ran the 40 in the 4.6 second range coming out of college, but both his touchdown runs this preseason have come when he's bounced plays outside and beat defenders to the perimeter.

He admitted that dispelling the notion that he lacks speed is important to him.

"I'm trying to a little bit," he said with a smile.

Hightower and James should prove to be a nice contrast in styles. James excels between the tackles and has great vision and agility. Hightower is more of a one-cut runner. He sees the hole and has a good burst.

Coaches have worked with both of them this summer on changes in the running game. One important facet will be improvement in running draw plays. The Cardinals weren't very good at it last year, and they've spent a considerable amount of time this summer working on those plays, as well as screens.

There have been signs of improvement, at least on draw plays. James gained 15 yards on one against the Chiefs in the second preseason game. The screen play, meanwhile, still needs work. The Cardinals traditionally have not run that play well, and that trend has continued this preseason.

The addition of Hightower should bolster the team's success in the red zone, already an area of strength. Last year, the Cardinals scored touchdowns 68 percent of the time they were inside opponents' 20. That ranked third in the league, behind the Patriots and Saints.

If Hightower can run outside as well as inside, the playbook will be wide open at the goal line. The Cardinals have two receivers, Larry Fitzgerald and Anquan Boldin, who can win single matchups there. Tight ends Leonard Pope and Ben Patrick are inviting targets there, too.

"As far as my role, I'm not sure what it is right now," Hightower said. "I'm just trying to go out there and have progress week to week."

CAMP CALENDAR: Camp ends Aug. 21. All training camp practices will be held at Northern Arizona University and are open and free to the public.