So the unit has been revamped, with the probability that there will be three new starters when the team opens the season.
The right side was supposed to be an area of great competition in training camp, but guard Paul Fanaika and tackle Bobby Massie have what appears to be a firm grip on the positions a week into workouts.
Lyle Sendlein, the Cardinals starting center for the past six seasons, is out for three weeks with a calf injury but is expected to be ready for the team's season opener against San Diego on Sept. 8.
Cooper, the seventh overall pick in last season's draft, was the only lineman to draw criticism from coach Bruce Arians on Saturday.
''I feel really good about the right side. Paul is playing really well right now and Bobby's been outstanding,'' Arians said. ''A little disappointed with where Coop is right now. I hoped he would come a little faster, to get back into the speed of the game.''
Arians said Cooper's problem is ''rust.''
''He didn't play for a year. He got 15 practices before he got hurt in this offense,'' the coach said. ''We need to see that special player that we drafted that we had last year.''
Cooper split time with Earl Watford with the first unit in Saturday's practice.
''I know that I haven't been playing up to the level of potential that I have,'' he said afterward. ''I mean, it's all right. He called me out and now I have to just work that much harder to kind of get over that hump and be the player I can be.''
Cooper said the problem has been consistency.
''There's sometimes when I'm showing flashes and I feel and I look like the old player I was prior to being injured,'' he said. ''Then there's sometimes and you can look and see 'That's not the guy we picked up.'''
Palmer was sacked a career-worst 41 times last season, his first with the Cardinals. After some shuffling of players, the situation improved somewhat.
But there was a clear need for improvement, and that sent Arizona after Veldheer, the 6-foot-8, 321-pound tackle who blocked for Palmer in Oakland.
''Twenty-six years old, he's mean, he's athletic, he's got all the traits,'' Arians said. ''... Hopefully the tackle situation is going to be put to bed for about eight or 10 years.''
Earlier in the week, the Cardinals signed 10-year NFL veteran tackle Max Starks, a starter on two Super Bowl winners in Pittsburgh.
Last year, the Cardinals signed right tackle Eric Winston just before camp started, and he became the starter.
But, for now at least, Starks is a backup behind Massie.
''I feel very confident in Bobby,'' Arians said. ''He's having a great camp.''
Starks plays both tackle positions, giving the team ''quality depth,'' the coach said.
The 6-6, 316-pound Massie, a fourth-round pick in 2012, has had a hard time adjusting to the NFL game. But that's changed this year.
''This is my year,'' he said. ''I'm tired of sitting on the bench and watching the game. I need to be out there playing. I feel like this is the best condition I've been in mentally, physically at any level of football. ''
Watford, a fourth-round pick last season, was groomed for the spot, but Fanaika is winning that competition, even though Watford is having a strong camp.
NOTES: Saturday was the team's Fan Fest, which concluded with a live goal-line scrimmage. ... Rookie wide receiver John Brown, impressive thus far, sat out practice for the second straight day with a sore hamstring. ... The Cardinals were awarded linebacker Trevardo Williams off waivers from the Houston Texans. Williams, a fourth-round pick out of Connecticut last year, missed all of his rookie season with a knee injury. To make room, Arizona released cornerback Todd Washington. ... The Cardinals have Sunday off, then resume workouts on Monday.
AP NFL website: www.pro32.ap.org and www.twitter.com/AP-NFL