ARLINGTON -- The Rangers have scratched pitcher Matt Harrison from Saturday's start against the Athletics because of soreness in his left shoulder. There is a strong possibility he could go on the disabled list, but the Rangers are going to wait at least a couple of days before making that decision.

The Rangers have shuffled their rotation as a result.

Brandon McCarthy was supposed to pitch on Friday in Game 1 of a doubleheader against the Athletics, but will be pushed back to Saturday. The Rangers are now undecided as to who will pitch Game 1, although it's likely they will call up Tommy Hunter from Triple-A Oklahoma City. Scott Feldman will still pitch Game 2.

Kris Benson is the leading in-house candidate, but the Rangers could have a need for their long reliever, either Wednesday night behind Derek Holland or on Friday during the doubleheader. Going with Hunter gives them more flexibility, which is why McCarthy was pushed back to Saturday.

Hunter, who is 1-2 with a 4.82 ERA in four Minor League starts, could be added to the roster on Friday in place of Harrison, who would go on the disabled list. After Hunter pitches Game 1, the Rangers could send him back to Triple-A and replace him with another reliever from Oklahoma City for the second game. That reliever would then be replaced by Vicente Padilla when he comes off the disabled list early next week.

"All of that is to be determined," pitching coach Mike Maddux said.

Harrison felt some shoulder stiffness before Monday's start against the Yankees but thought it was just normal. But he felt some "sharp pain" after the game in the front of the shoulder and that caused the Rangers to pull him out of Saturday's start.

"From what they tell me, it's nothing to worry about," Harrison said. "It's just early in the season, and they want to get it out of the way."

The Rangers will wait until Friday before making a decision on Harrison, but it does seem he's headed for the disabled list.

"It's a possibility," GM Jon Daniels said before Wednesday's game with the Yankees. "We'll see how he's doing tomorrow and how he's doing Friday. He'll just keep getting his treatments."

Harrison is the second Rangers starter to come down with shoulder soreness this month. Padilla is also sidelined with shoulder soreness, but he is expected to be activated early next week to pitch against the Yankees either Tuesday or Wednesday. Rangers starters lead the American League with an average of 100.3 pitches per game, but club officials do not believe an increased workload has been a problem.

"That's just not the case," manager Ron Washington said. "If you look at any team that's having success, it's because their starters are taking them deeper in the game. I know our guys haven't had this workload before, but now they're being successful and they can handle it."

Maddux said pitches per inning can be more stressful than pitches per game. From that standpoint, Rangers starters are ahead of the curve in averaging 16 pitches per inning, the fourth fewest in the league.

"I don't think anybody has had an increased workload," Maddux said. "Harrison pitched back-to-back complete games with [111 and 102] pitches. That's outstanding. It's not like he's been taxed to the extreme. Kevin Millwood came out of [Tuesday's] game with his shortest [5 2/3 innings] outing of the season after 98 pitches because he had his most stressful outing. A high number of pitches per inning is really what causes stress on the arm."