ARLINGTON -- Rangers rookie left-hander Robbie Ross threw 28 pitches in the bullpen without problem on Wednesday. Ross, has been on the disabled list since Aug. 30 with a strained left forearm and could come off the disabled list as early as Friday.

"We'll just see how he recovers tomorrow," Rangers manager Ron Washington said.

Ross is 6-0 with a 1.78 ERA in 52 games as the Rangers' primary left-handed reliever. Michael Kirkman has helped fill the void, posting a 0.75 ERA in his last 11 games while holding opponents to a .167 batting average. The Rangers are mulling the possibility of carrying two left-handed relievers on their playoff roster.

Adams likely unavailable for a few games

ARLINGTON -- Rangers reliever Mike Adams could be down for a couple of days while dealing with a sore trapezius muscle in the back of his right shoulder. Adams is the Rangers' No. 1 setup reliever.

Adams said he felt the muscle tighten up on Tuesday night while pitching the eighth inning in the Rangers' 6-4 victory over the Indians. Adams, called upon with the Rangers leading, 6-2, couldn't finish the inning.

"Once I got on the mound, it started tightening up," Adams said. "I warmed up fine, but all of a sudden on the mound it tightened up. I thought my stuff would be good enough to get through it, but I'm glad they got me when they did. I knew after three batters that it was going to be tight."

Adams faced five batters and allowed one run on one hit and two walks while recording two outs on 26 pitches. Koji Uehara took over and allowed a run-scoring single to Casey Kotchman before Tanner Scheppers struck out Michael Brantley to end the inning.

"I felt like I was shot-putting the ball," Adams said. "You always pitch in a little discomfort. You rarely pitch perfectly fine but last night more than usual it bothered me significantly. I couldn't finish my pitches. I'm taking today off for sure and let it calm down and go day by day for now. Last night we did some things [with treatment] to help move it along."

Adams has a 7.71 ERA in five appearances in September after going 2-0 with a 0.82 ERA in 12 games in August. Opponents hit .195 off him that month but are 7-for-19 (.368) so far in September.

With Adams out, Alexi Ogando and Scheppers become the Rangers' primary eighth-inning weapons. Left-hander Michael Kirkman is also an option. The Rangers are 72-1 this season when leading after seven innings.

Napoli still has two more rehab games

ARLINGTON -- Rangers catcher Mike Napoli had no problems in catching seven innings for Double-A Frisco in a 5-0 loss to Springfield in the first game of the Texas League championship series. Napoli, in his first game on medical rehabilitation assignment, was 0-for-2 with a hit by pitch.

Napoli followed that up Wednesday by going 1-for-4 with a home run and caught the entire game in a 6-4 loss. He is scheduled to be the Frisco DH on Friday n Frisco and could be activated after that.

"My intention is for him to play three games," manager Ron Washington said. "He needs to see pitching. He's catcher-ready. They put him through three or four days of work behind the plate. He needs to see live pitching and get his timing down."

Frisco lost to Springfield, 5-0, in Game 1 in the best-of-five series. So the series could be over after Friday. Frisco is the last Rangers farm team still going in the playoffs.

Napoli has been on the disabled list since Aug. 11 with a strained left hamstring. He is hitting .223 with 17 home runs and 40 RBIs in 92 games on the season.

Oswalt hopes to resume throwing

ARLINGTON -- Rangers pitcher Roy Oswalt is hoping to resume throwing on Thursday after taking three days off while dealing with a strained right forearm. Oswalt felt the problem come up early in Sunday's start against Tampa Bay.

"I'm going to throw a little tomorrow and see how it feels," Oswalt said. "I haven't done anything in the past few days except get treatment."

Oswalt, making his ninth start for the Rangers, lasted just two innings and allowed four runs on six hits and a walk. He is 4-3 with a 6.29 ERA with the Rangers while shuttling between the rotation and bullpen.

"It just cramped up and was tight the rest of the game," Oswalt said.

Oswalt has been on the disabled list eight times since the start of the 2003 season, but it has always been because of leg or back issues. He has never been sidelined for an extended period of time with an arm injury. He declined to speculate if shuttling between the rotation and bullpen was a factor.

Worth noting

• The Rangers have extended their working agreement with Triple A Round Rock for four more seasons. The Rangers switched their Triple A affiliation from Oklahoma City two years ago and are now locked in with Round Rock through 2018.

• Joe Nathan, after closing out Tuesday's 6-4 victory over the Indians, has now been successful on 30 straight save opportunities. He is 32-for-33 overall and his only blown save was on April 11 against the Mariners. He is the 14th different reliever since 1969 to have a streak of at least 30 straight successful save opportunities.

• Adrian Beltre has hit 18 home runs over each of the last two Septembers. That's the most for any Major League player. Orioles infielder Mark Reynolds is next with 13.

• Wednesday marked the sixth straight game that the Rangers have faced a right-handed starter. They have two more on the horizon before they are expected to face left-hander Jason Vargas for the Mariners on Saturday.