© 2014 MLB Advanced Media, L.P. All rights reserved.

4/23/2014 3:38 P.M. ET

Rangers could move Martinez to bullpen

OAKLAND -- The Rangers are not ready to option pitcher Nick Martinez back to Triple-A after his spot start against the Athletics on Tuesday night. Once Martinez recovers from throwing 92 pitches in the Rangers' 5-4 victory, he could end up in the bullpen.

Texas still sees Martinez as a starter in the long term, but the club is short one reliever in the bullpen after Pedro Figueroa went on the 15-day disabled list with inflammation in his left elbow. The Rangers are also without a long reliever after Hector Noesi was designated for assignment on Tuesday night to make room for Martinez.

Martinez went five innings against the Athletics on Wednesday and allowed four runs (two earned) on six hits, three walks and one strikeout.

"He did a heck of a job," manager Ron Washington said. "He really could have come unraveled. They made him work, but he did what he had to do."

Rangers acquire outfielder Robertson from Padres

OAKLAND -- The Rangers, looking to add speed to their bench and still unsure if Shin-Soo Choo needs to go on the disabled list, acquired outfielder Dan Robertson from the Padres for cash considerations on Wednesday.

Robertson replaces pitcher Pedro Figueroa, who was placed on the 15-day disabled list with left elbow inflammation. He has been sent back to Texas for an MRI and further examination by Dr. Keith Meister.

The Rangers were going to acquire Robertson regardless, as they were looking for an outfielder with speed after Jim Adduci went on the DL with a broken left pinky finger.

Robertson, a 5-foot-8 right-handed hitter, has never played in the Major Leagues. He is a career .304 hitter in seven Minor League seasons, with a .381 on-base percentage and a .411 slugging percentage. He also has 131 career stolen bases.

"He's got some speed and he can play all three outfield positions," Rangers manager Ron Washington said. "I can use him to pinch-run."

"We view him as a winning type of offensive player," assistant general manager Thad Levine said. "He's a very patient hitter and a scrappy performer. He fits the way [Washington] wants the game played and what he demands from his players."

Robertson could also serve as the Rangers' leadoff hitter if Choo ends up on the DL with a sprained left ankle. Robertson was a 33rd-round Draft pick by the Padres in 2008 out of Oregon State University. He has spent the past three seasons in Triple-A.

"This is every kid's dream," Robertson said. "You don't know how you are going to feel. It really hasn't sunk in yet. I'm sure it will sink in when my cleats hit the dirt."

Robertson was with Triple-A El Paso in Las Vegas when he got the call from Padres farm director Randy Smith. He was told it was good news and bad news.

"I said, 'OK, hit me with whichever one you want first,'" Robertson said. "He said, 'The bad news is we traded you to the Rangers.' I thought that wasn't so bad, I like Round Rock. Then he said, 'The good news is you're going right to the big leagues.'"

Harrison's debut pushed back to Sunday

OAKLAND -- The Rangers have finally set their rotation for the upcoming three-game series with the Mariners, and it is predicated on keeping Matt Harrison and Colby Lewis swinging a bat in Colorado on their next road trip.

So Robbie Ross will pitch on Friday, and Lewis will start on Saturday. Harrison's debut, originally scheduled for Friday, will be pushed back to Sunday. He will be making his first start since April 6, 2013. That leaves Yu Darvish, Martin Perez and Ross to pitch the three-game series against the Athletics next week in Arlington.

Lewis, Harrison and Darvish would pitch against the Angels the following weekend in Anaheim. That would also mean Lewis and Harrison do not pitch in Colorado during a two-game series on May 5-6. That turned out to be the deciding factor in the Rangers setting up their rotation.

"We don't want them on the basepaths and we don't want them swinging the bat, so we had to adjust it," manager Ron Washington said. "We don't need Harrison swinging and missing and we don't need Colby running the bases, because we know he can hit."

Harrison understands the Rangers' concerns after missing almost all of last season because of a herniated disk in his lower back. He already had one setback early in Spring Training, and he doesn't need another one.

"I haven't swung the bat in a long time," Harrison said. "This gives me time to see how I recover from pitching every five days. I'm just glad to get back. The way I felt last year, I didn't know if I would ever pitch again."

Feliz shut down after experiencing fatigue

OAKLAND -- The Rangers have shut down pitcher Neftali Feliz from throwing, and the right-hander has returned to Arlington. Feliz, who was pitching for Triple-A Round Rock, is dealing with general fatigue and the Rangers want him to spend time in a rehab program with medical director Jamie Reed.

Feliz had Tommy John elbow reconstruction surgery on Aug. 1, 2012, and he has still not returned to the level he was at in 2010-11, when he was the Rangers' closer. Feliz pitched in six games with the Rangers but did not make the team in Spring Training. Instead, the Rangers sent him to Round Rock to build up stamina and work on his mechanics.

"There is no real injury to report, except general fatigue," assistant general manager Thad Levine said. "We're trying to deal with that so it doesn't manifest itself into a real injury. We feel he will be back on the mound soon. We don't see this as a prolonged situation."

Feliz hasn't pitched for Round Rock since April 16. He has appeared in five games, posting a 1.59 ERA. He has allowed two hits and two walks in 5 2/3 innings, while striking out six.

Worth noting

• Third baseman Kevin Kouzmanoff was out of the lineup on Wednesday with some lingering stiffness in his back. Josh Wilson started at third base for the third time this season with Donnie Murphy at second. Kouzmanoff had to come out of Tuesday's game in the fourth inning when his back tightened up on him. He could be ready by Friday but the Rangers also expect to activate Adrian Beltre from the DL that day.

• Choo was also out of the lineup for the second straight game while dealing with his sprained ankle. The Rangers are waiting until Friday to reevaluate Choo, but they also have to make a roster move that day to activate Beltre.

Said Choo: "When I first came out of the game, I thought it was more than a couple days. I thought it was a more serious injury. The first day, I couldn't even walk. Today, I feel better. I'm trying to be cautious. I'll try to do more, but this is a long season. I don't want to make it worse. If I'm comfortable to play, I will."

• When Murphy started at designated hitter on Tuesday night, he was the seventh different player used by the Rangers in that slot. Their designated hitters have combined for a .341 average, the highest in the American League.

T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.