Carson Palmer will have a hard time improving on his brief performance in last week's preseason opener, but the Arizona quarterback will have more time to work.

Palmer, 4 for 4 for 70 yards in an 80-yard touchdown drive in his only possession against Kansas City, is to play the entire first quarter Saturday night against the Chargers at University of Phoenix Stadium.

The Arizona first unit will have three new members: right tackle Bradley Sowell, left guard Ted Larsen and rookie nose tackle Rodney Gunter.

Sowell, the starter at left tackle two years ago, moved ahead of Bobby Massie, who reportedly is facing a three-game suspension for violating the NFL's substance abuse policy. Massie, arrested on a DUI charge at Cardinals headquarters the night before the Super Bowl, has been splitting time with first-round draft pick D.J. Humphries with the second unit. The NFL has not announced the suspension, but a person close to the situation told The Associated Press that Massie had appealed the three-game suspension.

Larsen steps in for Mike Iupati, who will undergo surgery to repair a meniscus and will be out up to eight weeks. Gunter, a fourth-round draft pick from Delaware State, replaces Corey Peters, out for the season with a torn left Achilles tendon.

Coach Bruce Arians said he hopes to get newly signed Chris Johnson five or six carries. Rookie RB David Johnson, who had missed most of camp until this week with a hamstring injury, will play most of the second and all of the third quarter.

Chargers RB Melvin Gordon, the 15th pick overall, expects to play despite missing Wednesday's practice with a sprained right ankle. "Just go out there and be sharp. That's the whole thing about training camp, is to go out there and be clean on anything you do," he said.

Gordon had a limited role in Thursday's practice before the Chargers broke camp. He carried six times for 11 yards in last week's exhibition opener against Dallas.

Coach Mike McCoy declined to say if he'll start the same offensive line as last week. D.J. Fluker has moved from right tackle to right guard, and free agent pickup Joe Barksdale is now at right tackle. McCoy says Fluker has done "a nice job" at guard.