ARLINGTON -- The Rangers have sent left-handed reliever A.J. Murray back to Triple-A Oklahoma.

Murray was optioned after the Rangers 5-3 victory over the Kansas City Royals on Tuesday to make room for pitcher Vicente Padilla.

Padilla is being activated from the disabled list to start on Wednesday against the Royals. Murray was sent down with a record of 0-1 with a 7.94 ERA in six games. He was called up when the Rangers included Ron Mahay in a July 31 trade with the Atlanta Braves.

Murray's demotion leaves the Rangers with John Rheinecker as their only left-handed setup reliever. Rheinecker started on Saturday against the Tampa Bay Devil Rays and pitched six innings, but the Rangers expect him to be ready to pitch in relief if needed on Wednesday.

C.J. Wilson had been the other left-handed setup reliever but he has taken over the setup role and picked up his fifth save on Tuesday night.

The Rangers have five right-handed relievers in Joaquin Benoit, Frank Francisco, Wes Littleton, Willie Eyre and Jamey Wright. But they'll have to make another roster move on Saturday when Kameron Loe is activated off the disabled list.

Pitching updates: Kason Gabbard did not throw his bullpen session Tuesday, but will be ready to start on Friday against Minnesota. Gabbard left Sunday's game after throwing 18 pitches with left forearm stiffness.

"It's nothing to be worried about," Gabbard said.

Pitching coach Mark Connor is not worried about Gabbard either, who has had four arm surgeries in his career.

Vicente Padilla, on the disabled list with right triceps irritation, will start on Wednesday against Kansas City. Padilla last started on June 21. In six rehab starts at Double-A Frisco, he allowed 11 earned runs in 12 innings.

"We hope he throws well," Connor said. "The Minor League starts don't indicate he's back to where he needs to be, but those are Minor League starts. Some guys don't pitch very well in those starts."

Connor said Padilla would give the Rangers, at most, five innings on a 75-80 pitch count.

Reliever Akinori Otsuka has thrown on flat ground with "minimal effort" since going on the DL on July 19 with right forearm inflammation. He might not pitch again this season.

"I don't know [if he will]," Connor said. "I sure hope he does -- for his confidence and to show people he is healthy heading into the off-season."

Before Otsuka can return, he will need to throw 100 percent effort on flat-ground, then throw two or three bullpen sessions and a simulated game before making two or three rehab appearances.

"If he comes in tomorrow and says he's ready to go, [then] Sept. 1 is still a possibility," Connor said. "But it's all going to depend on how he feels."

Loe made a rehab start on Monday at Double-A Frisco, allowing three runs (two earned) on one hit in three innings. He issued five walks to just one strikeout.

"Honestly, that umpire was the worst I've ever seen," Loe said. "The line doesn't look great but I'm ready to go -- my back felt really good."

Loe is scheduled to start on Saturday at Minnesota.

Sosa vs. Santana: Sammy Sosa will start on Thursday against Royals right-hander Leo Nunez. He is also scheduled to start on Sunday at Minnesota against Cy Young winner Johan Santana.

Santana is 3-2 with a 5.02 ERA against the Rangers in his career. That's his highest ERA against any American League team.

Sosa hit a home run in his lone at-bat against Santana earlier this year. Sosa is also hitting .318 against lefties.

Battle of Guitar Hero: Rangers reliever C.J. Wilson hosted a Guitar Hero II tournament on Monday at the House of Blues in downtown Dallas to benefit the Texas Hemophilia Summer Camp. Teammates Wes Littleton and Jason Botts also attended the event.

"Anything we can do to get that age group [15-30 year-olds] involved is better," Wilson said.

Wilson said because of the event's success, he has two more events planned -- one shortly after Halo 3 is released Sept. 25, and another when Guitar Hero III is released this fall around Halloween.

He said it: "It's cool but nothing that's a huge landmark. My most memorable home run was probably my first one in Dodger Stadium [June 11, 2001]. It's the stadium I watched growing up and had lots of family and friends there. It was off Luke Prokopec." -- shortstop Michael Young, on hitting career home run No. 100 Sunday against Tampa Bay.

Monday's Minor League stars:

Gold: Third baseman Chris Davis went 3-for-3 with two home runs, a double, three runs scored and four RBIs as Double-A Frisco defeated Wichita, 7-3.

Silver: Second baseman Matt Lawson had three hits and scored two runs as Class A Spokane lost to Tri-City, 6-5.

Bronze: Designated hitter Jonathan Greene went 2-for-5 with a home run and three RBIs for Spokane.

Briefly: Manager Ron Washington said he wants to have the players hit inside on Wednesday and Thursday to avoid the heat, which is suppose to climb to 102 degrees Wednesday and 92 degrees Thursday. In the last series against Tampa Bay, Washington felt the team played sluggish in the second game because of the heat. ... Hank Blalock did not throw Tuesday, but is scheduled to on Wednesday. ... Saturday's game in Minnesota will start at 6:35 p.m. to accommodate a pregame ceremony.

Up next: The right-handed Padilla pitches for the Rangers against right-hander Gil Meche of the Royals. First pitch is scheduled for 7:35 p.m. CT Tuesday at Rangers Ballpark in Arlington.