ARLINGTON, Texas -- One bad inning did in Tanner Scheppers on Saturday. He gave up all five of his runs in the fourth inning during a 6-5 loss to the Houston Astros.

Scheppers ended up going seven innings and collected a career-high six strikeouts with one walk. But that one inning cost him dearly.

"I want to go out there, attack with my fastball and go from there," Scheppers said. "I think at the end of the day, I've got to keep my faith in my ability, go out there and use my strengths, keep the ball on the ground and have the offense score some runs."

Scheppers wants to take the positives from his last outing and apply them, but the reliever-turned-starter knows he also has to get results. He's learning about making the adjustments from the bullpen to the rotation.

"Your mistakes are under a microscope," Scheppers said. "You make a mistake and they take advantage of it and it can hurt you. It's about minimizing those mistakes, keeping the game slow and focusing on each pitch."

Rangers manager Ron Washington sees a pitcher who is getting closer to putting it all together.

"He has to minimize the damage," Washington said of Scheppers' rough inning. "He's getting better. It's a learning experience for him. He's used to coming in, going one inning, rushing through it and leaving everything out there. Now he's going through a lineup three or four times.

"You expect an inning to get away. But if it gets away you hope it's two runs, not five."

Rios will stay aggressive: Outfielder Alex Rios said he's going to continue to be assertive on the bases, even with Prince Fielder hitting behind him. Rios was at first base Tuesday with Fielder up and tried to steal second and was thrown out, eliminating Fielder's chance to try to move him around the bases.

"I'm not going to quit being aggressive on the bases," Rios said. "I'm going to do what I can do to advance and make it easier for him with me in scoring position. I thought I had a good jump, but he had a good pitch to throw me out. I had a great chance, but it was a good throw."

The pitch was up and away, almost like a pitchout, and catcher Mike Zunino made a great throw. Zunino also got Elvis Andrus trying to steal.

"That Zunino kid can throw. I've read stuff about him and now I'm seeing it," Washington said. "Maybe we need to stop trying to run on him."

Bullpen improving: It was a rocky first nine games for the Rangers bullpen. Neal Cotts and Alexi Ogando struggled and the relievers as a group put up a 6.21 ERA in those first nine games. Opponents were hitting .288 against them. But things have improved dramatically since then.

In the six games of this homestand, the bullpen has a 0.60 ERA (one earned run in 15 innings) and opponents are hitting .208. Cotts has pitched better recently, and Ogando earned his first save since 2012 Sunday against Houston. And Pedro Figueroa came in and got a 1-2-3 eighth inning Wednesday, keeping it a two-run game before the Rangers were able to come back.

"What's expected of them is starting to fall in place a little better," Washington said. "The main guys are starting to put it together."

Washington has been pleased with Shawn Tolleson, who is one of the secondary pieces in the bullpen. Tolleson has allowed one run in his 5 2/3 innings of work and it came in his debut on Opening Day.

"I'm still feeling him out," Washington said. "When the bullpen is down, we'll need one of those guys in a big situation. As long as Cotts, [Jason] Frasor, Ogando and [Joakim] Soria are available, they'll get it. When they're not, he'll get a chance to fill in. My first impression has been favorable since spring training. He's got pitches. He's got a split, changeup, doesn't throw the ball down the middle of the plate and has an idea of what he's doing."