ARLINGTON -- Adrian Beltre, on the 15-day disabled list with a strained left hamstring, is running the bases but not at full speed. Running the bases is usually the last thing a player does before returning from the disabled list, but that's not the case right now with Beltre.

He has not been given the clearance from Dr. Keith Meister to go full speed yet and it's almost a certainty that Beltre won't be ready until after the rosters expand in September.

"He's going through the process of trying to build up stamina," manager Ron Washington said. "He is continuing to run the bases until he builds up leg strength and we can trust it."

Beltre has been on the disabled list since July 23. He was close to returning before aggravating the injury on Aug. 6.

"Hamstrings are funny," Washington said. "He found that out the first time. When he comes back, it will be when he is ready. We just don't know when that will be."

Rangers plan to add 'pen arms in September

ARLINGTON -- The Rangers will discuss September additions this week and are expected to add at least a couple of relievers to their bullpen once the rosters are expanded. One or two may come right away, while others may have to wait until Triple-A Round Rock is finished with the playoffs.

"We want to be respectful of that," general manager Jon Daniels said.

Darren O'Day is almost certainly to be one callup. He is 1-0 with a 2.13 ERA in 18 games with Round Rock, holding opponents to a .213 average while striking out 27 in 21 1/3 innings. He was called up earlier this month when Alexi Ogando went on paternity leave. Another candidate is right-hander Tim Wood, who was claimed off waivers from the Pirates last week.

Some of the other candidates have been here already while others might be new faces. Pedro Strop has been pitching well since the All-Star break, posting a 1.80 ERA with a .211 opposing batting average and 20 strikeouts in 15 innings. Cody Eppley has a 0.73 ERA in his last 10 appearances.

The one guy on the 40-man roster who has struggled is left-hander Michael Kirkman. He has a 4.57 ERA in 11 games since the All-Star break and has walked 18 in 21 2/3 innings. He is not positioning himself well to be a September callup, but the southpaw has had success at the big league level.

The Rangers have only one left-hander in their bullpen, so Beau Jones could be a more viable candidate. He has a 2.05 ERA since the All-Star break, a 1.38 ERA in August and left-handed hitters are batting .232 off him. Calling him up in September would also give the Rangers a chance to evaluate him for next season.

One right-hander to watch is Mark Hamburger, who was acquired from the Twins for reliever Eddie Guardado in 2008. Hamburger is 4-0 with a 1.72 ERA in his last 12 games and has made three straight starts. That has allowed Round Rock to stretch him out to six innings in case the Rangers need another long reliever in September.

Jones and Hamburger are not on the 40-man roster, but Daniels said the Rangers will find a way to create roster space in September if they need to add somebody.

Saltalamacchia impressing former manager

ARLINGTON -- Jarrod Saltalamacchia was the Rangers' Opening Day catcher last season, but a right shoulder injury and throwing problems cost him the job. He was traded to the Red Sox at the Trade Deadline last season and now he is playing regularly. He is also impressing his former manager.

"He's doing a real good job, you can tell," Rangers manager Ron Washington said. "He looks confident and he's over his throwing woes. He made a good throw [in Monday's game] to third and I was watching his throws to second. They were crisp and sharp. He's getting the ball back to the pitcher."

Elvis Andrus tried to take advantage of Saltalamacchia on Monday, but it didn't work. Andrus was on first and Ian Kinsler was on third with one out in the third inning. Andrus and first-base coach Gary Pettis saw Saltalamacchia lobbing the ball back to the pitcher. Andrus decided to take advantage and try to steal second on the throw back to the pitcher. Instead, he went too early and Saltalamacchia picked him off first.

"I went a little bit before, maybe a second before he threw the ball, and I was supposed to wait until he released the ball," Andrus said. "That's going to happen. I'm really aggressive on the bases, and I learn from that. Hopefully that doesn't happen again."

Saltalamacchia said he thought Andrus was up to something.

"Most guys, when you catch the ball, they try to run back," Andrus said. "They don't want to get picked off. He kind of stood there. In the back of the mind, I was like, if they try it, at least I can maybe pump fake and make him think ... if they do that again, make them think I'm throwing it to the pitcher and hopefully they go. And Elvis did. He stood off the bag, and I kind of faked it."

Worth noting

• Pitcher Ryan Tucker was placed on the disabled list with elbow irritation at Triple-A Round Rock and utility infielder Matt Kata was activated.

• Mavericks head coach Rick Carlisle, who led his team to an NBA title, threw out the ceremonial first pitch before Tuesday's game.

• Among Major League players with a minimum of 300 plate appearances, Mike Napoli went into Tuesday's game ranked third with a .978 OPS, a .593 slugging percentage and 13.00 at-bats per home run.

• C.J. Wilson is 7-0 with a 1.81 ERA in 10 August starts over the past two seasons.