Steven Sheffield and Taylor Potts hoped this week would be another opportunity to determine Texas Tech’s signal caller on Saturdays this fall.

But now, the two seniors are just trying to stay healthy.

The Red Raiders were hit by their first dilemma this spring when Tommy Tuberville announced Sheffield is expected to miss eight to 10 weeks after re-injuring his left foot in practice Monday when he stepped on a teammate’s foot. Sheffield underwent surgery Wednesday morning on the same foot he injured against Nebraska in October.

A few hours after Tuberville broke the news about Sheffield, Potts left the field with a cut in between his fingers on his throwing hand. Tuberville said Potts hit his hand on a helmet, causing the cut. The cut requires stitches and could keep him out until the middle of next week.

“I’ve seen that happen to them,” Tuberville said of Sheffield’s injury. “They get a string of bad luck and hopefully this is all his. Maybe he’s used it all in one year.”

Tuberville said the senior had a screw replaced in his foot, and he should be ready by June, right before fall camp.

As far as coaches evaluating Sheffield and Potts, the injuries may come at an inopportune time. Tuberville said he plans on running a 40- to 50-play scrimmage Friday.

There are countless storylines as spring practice continues, but one of the most noteworthy may be the quarterback battle.

Potts and Sheffield virtually took turns at quarterback last year, with both players seeing significant time throughout the season. Potts was named starter at the beginning of the 2009 season, but a concussion in the New Mexico game stalled his season and Sheffield’s walk-on-to-starter story took center stage.

But after helping Tech cruise past New Mexico and leading the Red Raiders in routs of Kansas State and Nebraska, Sheffield was sidelined with the injury.

Since the Oklahoma State game last year, the two have gone back and forth as starter, which has spilled into spring practices.

Coaches insist Sheffield’s injury will not impact who wins the starting job. Tuberville said at the beginning of spring practices and on Wednesday that the battle at quarterback will go deep into two-a-days.

It was just Saturday when Sheffield impressed coaches by completing 18-of-25 passes for 222 yards and two touchdowns in Tech’s first spring scrimmage. Potts was solid as well, completing 13-of-25 passes for 141 yards and a score.

“It’s probably going to put us at a standstill in terms of not knowing what Steven can do other than what we saw for about five practices,” Tuberville said.

Now the spotlight is on redshirt freshman Jacob Karam and sophomore Seth Doege.

Tech offensive coordinator Neal Brown said first Doege, then Karam will take most of the reps in Friday’s scrimmage.

Doege might be used to this after last season, when he started against Kansas. Although he didn’t finish the game, he completed 14-of-28 passes for 159 yards and a touchdown.

“Doege and Karam are going to both get some reps and to be honest with you, that’s a good thing,” Tech offensive coordinator Neal Brown said. “They need it. They need some work. So we’ll roll them out there.”

As a former Tech quarterback, inside receivers coach Sonny Cumbie knows what Sheffield is going through.

Cumbie said Sheffield’s situation is a tough one, but considering the senior’s experiences last season — and in his Tech career — he should come back with no problems.

“It gets you down a little bit,” he said. “But he’s overcame a lot. He was a walk-on. He was injured la