ARLINGTON, Texas -- The big inning bit Tanner Scheppers again Thursday. The question now is whether Scheppers will start another inning in the rotation.

Scheppers said he isn't worried about whether he'll hang onto his job, and manager Ron Washington indicated the plan -- at least right now -- is for Scheppers to make his next start in Oakland next week.

"It's nothing that's crossed my mind," Washington said when asked if he was considering moving Scheppers out of the rotation. "We know it's a work in progress. "

The Rangers staked Scheppers to a 4-0 lead and he couldn't hold it. Back-to-back home runs by Robinson Cano (his first with the Mariners) and Corey Hart tied the score in what ended up as a six-run third inning in the Rangers' 8-6 victory. Scheppers retired just one of the seven batters he faced in the third inning. Hector Noesi gave up a double to score the final two runs on Scheppers' ledger. Scheppers was finished after 66 pitches, but the Rangers' bats and the bullpen bailed him out.

"Those were not good pitches," Scheppers said. "They capitalized on it. They are good hitters and they are going to hit mistakes. Sometimes you get beat and you've got to tip your cap and focus on the next one and continuing working."

In three of Scheppers' four starts, one inning has cost him. He allowed a six-run inning on Opening Day, the five-run fourth against Houston in his last start and a six-run third Thursday. So 17 of the 20 runs that Scheppers has allowed this season have come in three innings.

Scheppers' next turn in the rotation comes Tuesday in Oakland, the middle game of that three-game series. It's likely the Rangers will look at their options, and if they decide to make a change, Nick Martinez is the logical choice. He pitches tonight for Double-A Frisco, and assuming he has no issues, he'd be on schedule to pitch in Scheppers' spot Tuesday. Martinez made his big league debut in Tampa Bay and allowed three runs on four hits in six innings with three strikeouts, three walks and two homers. It was a solid debut with family watching, though the Rangers lost the game, 5-4. Nick Tepesch and Scott Baker are in Triple-A as possible options.

Matt Harrison isn't quite ready and is slated for a rehab start Saturday at 95 pitches. Rangers general manager Jon Daniels said before Thursday's game that Harrison would likely need more than one rehab start. But that could depend on how he does and feels Saturday. If he's deemed ready, he could slide into the rotation in Seattle and Martinez would be needed for just the one start.

Scheppers was stretched out as a starter this spring and pitched well while Alexi Ogando didn't. Scheppers earned the rotation spot while Ogando went back to the bullpen. But Scheppers hasn't been able to find any consistent success so far this season. He's allowed 20 runs in 18 1/3 innings for a 9.82 ERA. Scheppers has walked seven batters and struck out 13 and has also given up four homers -- including two three-run shots and a grand slam.

Perhaps the Rangers will determine that it's too early to give up on Scheppers. In the past, they've given guys more than four starts to try to get things together. But discussing their options seems prudent, especially considering Scheppers was a valuable part of the club's bullpen last season and can be again as a setup man and possible closer in the future. They could simply decide to let wait until Harrison is ready and at least give Scheppers one more start. Stay tuned.