UH officials believe Patton will miss the remaining eight sessions of spring practice. But Patton vowed to return by the May 1 intrasquad scrimmage, the last event of spring practice.

"It's really disappointing," said Patton, who missed most of last season because of an injury to the same right hamstring. But Patton said this injury is "a little different from my first hamstring (injury). It's in a lower area. It's bad luck. I have to work through it."

Patton also was a candidate to play nickelback when the Warriors employ five defensive backs.

Patton's expected absence opens the way at right cornerback for Omega Hogan, Ray Bass, Cameron Hollings-worth and Ernest Powell.

"Omega automatically moves up (to No. 1)," said Rich Miano, who coordinates UH's pass defense. Patton's injury "gives those guys a chance, and it develops our depth."

Hogan, a fourth-year junior from Houston, has pushed for more playing time this spring. "I've been patient," he said. "I've worked on my stuff. Once I get my time, I want to be perfect."

Hogan said UH's defensive schemes have become second nature.

"Coach (June) Jones said, 'You can't play fast unless you know all of the plays,' " Hogan recalled. "I want to play fast."

Patton had worked extensively to rehabilitate the original hamstring injury. Although rehabilitation can strengthen the surrounding muscles, a pulled hamstring leads to scar tissue and increases the probability of a recurrence.

"Hopefully, this is not a chronic thing," Miano said.

Patton was competing in 7-on-7 drills when he suffered the injury. "I was running and I tried to hit fifth gear and it kind of strained on me a little bit," he said.

He was assisted off the field, and did not compete in the controlled scrimmage. He received treatment at the training room, but was limping noticeably afterward.

• Spring flings: Yesterday's controlled scrimmage served as the first significant test of spring practice for the four quarterbacks competing to serve as the top backup to Tim Chang.

Kainoa Akina, a fourth-year junior, completed 5-of-6 passes, throwing the only touchdown. Fourth-year junior Jeff Rhode was 6 of 9. Ryan Stickler, a third-year sophomore, was 3 of 5, but sacked twice. Jack Rolovich, a second-year freshman, rebounded from an erratic start to complete 2-of-5 passes for 47 yards in the second stage.

"They kind of settled down and started to make good decisions," said Dan Morrison, who coaches the quarterbacks.

In the previous six practice days, the offense faced a skeletal defense in drills. In the controlled scrimmage, "the intensity was higher," Akina said.

"The defensive guys are trying to get starting spots, so they're working their butts off, too," Rolovich said. "It was just a battle out there."

This spring, Akina, who is the best scrambler of the four, has showed off his improved arm strength. Stickler and Rolovich appear to be reading defenses better. Rhode has benefitted from receiving more snaps. Rhode no longer hesitates in the pocket.

"I really feel good out there," Rhode said. "When the coaches look at the film to see who made a good throw, hopefully my name comes up."

Although Akina entered spring training as the No. 2 quarterback, each quarterback is receiving the same number of snaps. The rotation also changes every day.

"We're charting them," Morrison said. "We're not worried too much about a hierarchy. We want to make sure all four of them are getting better."