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04/19/2013 8:55 PM ET

Ortiz making name for himself in Rangers' bullpen

ARLINGTON -- Rookie reliever Joe Ortiz wears the pink backpack on the way to the bullpen just like fellow lefty Robbie Ross did last year as a rookie, and Ortiz is pitching just as effectively as Ross did in his surprising first season.

Ortiz leads all AL pitchers with 10 2/3 innings pitched in relief, the last 8 1/3 of them scoreless. His 0.84 ERA is the best in Texas' bullpen.

The 5-foot-7, 22-year-old seems rather fearless on the mound, Ross said.

"He's doing exactly what he needs to do [as a rookie]," Ross said. "Go after them, do what you have to do and make it easy, don't try to make it too complicated."

Manager Ron Washington has been impressed with Ortiz's demeanor as well.

"He gets outs and he gets them quick," Washington said. "He acts like he has no pulse, really."

Washington wants to avoid overusing Ortiz, though.

"By the time Robbie got to the All-Star break [last season], he was blown out," Washington said. "We've got to try to monitor it [with Ortiz]."

Rangers look to pick up timely hitting

ARLINGTON -- The Rangers headed into their series against the Mariners hoping they could find the offense at home that had seemed to elude them during much of their six-game road trip through Seattle and Chicago.

Texas hit just .237 (9-for-38) with runners in scoring position in the previous four games. Much of the Rangers' lineup has been struggling in that situation all season -- David Murphy is hitting .235, Adrian Beltre is at .167, A.J. Pierzynski is at .143 and Mitch Moreland is hitless in seven at-bats.

"If those guys get going and get consistent, things will work out," manager Ron Washington said. "Those are the ones that we depend on right now that are not where we'd like to have them or where they'd like to be. It happens in the game."

Fifteen games into the season, the Rangers were averaging 3.7 runs per game, down from 5.0 last season when they scored an American League-best 808 runs.

"If the offense had been swinging the bats up to its capability, we could have a lot better record than we do now," DH Lance Berkman said. "We really haven't gotten into a good groove as a team offensively. I feel like that'll come, and when it does, it'll benefit us. I'd like to see it sooner rather than later."

Tepesch hopes to learn from mistakes in next start

ARLINGTON -- Rookie Nick Tepesch will make his third career Major League start Saturday, but he'll be facing a team he's already pitched against -- the Seattle Mariners.

Tepesch left after 5 2/3 innings, nine hits and four earned runs, shouldering the loss in Seattle last Sunday.

"It's a little bit of a challenge" to face the same lineup again, Tepesch said.

Sunday was a step back from his debut, when he allowed one run in 7 1/3 innings to beat Tampa Bay, but Tepesch said he learned from both outings.

"I feel like I've definitely gotten a little more comfortable since I've been here," Tepesch said. "The first one, I didn't really make as many mistakes. The second one, just leaving the ball over the plate. That was the biggest difference between the two."

Berkman back in lineup despite sore knee

ARLINGTON -- After sitting out three games at Wrigley Field, Rangers designated hitter Lance Berkman was back in the lineup Friday -- sore knee and all.

Berkman, 37, underwent two left knee surgeries last season and said he's OK with not playing every day in order to stay healthy.

"Whenever you get to be a certain age with a certain injury history, you certainly have to be cognizant of overuse and overexertion," Berkman said. "I didn't play last year, really, and so part of this year's going to be finding my stride again. How many games can you play in a row? How much pressure can you put on that joint before it starts to give you problems? It's always better to be cautious in the early going because you can reap a dividend from that later."

Berkman said his knee has been bothering him more than it did this spring, but, "some of that's probably the weather conditions we've been playing in." He did not play first base during the Interleague series, though he said he could if necessary.

"I think I could do it," Berkman said. "I have had some trouble with my knee being sore just from DHing, so I'm a little bit hesitant to say I can run out there two or three or four nights in a row. But if they said, 'Hey, we absolutely have to have you play first base for a game,' I could certainly do it."

Worth noting

• Manager Ron Washington said he called Julio Borbon, who was claimed by the Cubs on waivers Friday.

"I called him and wished him all the luck in the world," Washington said. "He shouldn't be going in there to try to prove anything to anyone. He's already done that."

Dave Sessions is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.