ARLINGTON -- The Rangers are trying to figure out what's wrong with Triple-A Round Rock third baseman Mike Olt and Double-A Frisco pitcher Cody Buckel.
Olt, the No. 2 ranked prospect in the farm system by MLB.com, is undergoing tests on his eyes after he reported some vision problems over the weekend. He has not been in the Round Rock lineup since Thursday. Olt is currently hitting .139 with one home run and six RBIs in 20 games. He has struck out 32 times in 72 at-bats and the Rangers can't help wonder if his vision has been a factor.
"It would make more sense," general manager Jon Daniels said. "But we'll wait until we get an official diagnosis and hold off any conclusions."
Buckel, who is the club's No.4 prospect, is healthy but pitching poorly at Frisco. So the Rangers are going to put him in the bullpen to see if he can work out his problems. He has walked 25 batters in nine innings over five starts.
"He's been putting the bullpen in a tough spot, making them pick up a lot of innings," Daniels said. "It's the nature of the game. Guys have ups and downs. There aren't too many guys who get there without any hiccups."
Beltre not concerned with slow start at the plate
ARLINGTON -- Rangers third baseman Adrian Beltre said he considers himself a "slow starter." From a statistical standpoint, that has not always been the case, but it certainly has been this season.
Beltre went into Tuesday's game with the White Sox hitting .239 with a .418 slugging percentage. Throw in a .293 on-base percentage and Beltre's .711 OPS for the month is his lowest since a .515 OPS in 2009 with the Mariners.
But Beltre hit .321 with a .356 on-base percentage and a .543 slugging percentage during April 2012, so just being a "slow starter" seems insufficient to explain what's going on with him at the plate this month.
"It's a long season, but the bottom line is I don't want to be struggling," Beltre said before going 1-for-4 with a two-run homer in the Rangers' 10-6 victory over the White Sox. "I know I'm not swinging the way I want to, but I know it's a long season and it may kick in at any time. I have always been a slow starter. I think in 16 years I've only had four or five seasons where I started off with a hot streak.
"The one thing I don't worry about is me. I know I'm going to be fine. I've been through this enough to know not to drive myself crazy with anything. I'm hitting some balls hard but right at people. Once I find holes, things will change."
David Murphy has had rough Aprils before as well. He was 3-for-31 during April in 2009 and 6-for-37 in 2010. He went into Tuesday night's game hitting .170, although that was done in 88 at-bats. That's the concerning part.
"April has not been a good month for me, but this is a little more prolonged," Murphy said. "I still have the feeling I'm going up there with every at-bat thinking this is the at-bat that I'm going to break out. It's definitely frustrating, but what can you do?"
Pierzynski sits out with bruised right oblique
ARLINGTON -- Catcher A.J. Pierzynski was out of the lineup against his former team on Tuesday because of some soreness and bruising in the oblique muscle in his right rib cage. He may sit out again on Wednesday with left-hander Chris Sale on the mound for the White Sox.
Pierzynski has been dealing with occasional problems on that side of the rib cage for several years and he missed a series against the Rangers last season because of the problem. This time it has been bothering him for the past couple of weeks.
Pierzynski has been getting treatment for the problem and was examined by Dr. Keith Meister on Monday. But the treatment has caused some extra bruising in the area and the Rangers want to address that before Pierzynski plays again.
"We have some color in there that we're trying to get rid of," Pierzynski said. "We've been playing with it and we're trying to be proactive because of the bruising. I've had it before. ... It's been there and then it goes away."
Pierzynski said the problem arises only on certain pitches when he is swinging the bat.
"It more of only when I swing," Pierzynski said. "I can throw, catch, run, I can do anything else."
Geovany Soto made his sixth start at catcher on Tuesday and will likely be behind the plate on Wednesday. Pierzynski is hoping to play on Thursday against his former team. He spent eight years with the White Sox before signing with the Rangers as a free agent this offseason.
"It's killing me not to be out there, especially against [the White Sox]" Pierzynski said. "I've been looking forward to this series. Unfortunately, today was not meant to be."
Right-hander Wells ready to hang up cleats
ARLINGTON -- Triple-A Round Rock pitcher Randy Wells has told the Rangers that he is retiring. Wells, 30, was 0-4 with a 6.08 ERA in five starts for the Express.
"He just didn't have the same level of desire," general manager Jon Daniels said. "It was a tough decision, but he didn't feel he was doing a service to the team."
Wells has three-plus years of Major League service, almost all of it with the Cubs from 2008-12. He has made 86 Major League starts and 12 relief appearances with a career record of 28-32 with a 4.08 ERA.
The Rangers signed him early last offseason to a Minor League contract with an invitation to Spring Training. He came to camp as a candidate for the rotation but was sent to Round Rock when Nick Tepesch won the fifth spot in the rotation.
• John Lackey has made more starts against the Rangers than any active pitcher. He has a chance to pad his lead over Felix Hernandez because he is scheduled to pitch for the Red Sox on Saturday at the Ballpark in Arlington. The Red Sox rotation for the weekend series against the Rangers is set up for Felix Doubront to pitch Friday, Lackey on Saturday and Jon Lester on Sunday. The Rangers are scheduled to miss Clay Buchholz and former teammate Ryan Dempster.
• Martin Perez, who is pitching in extended spring workouts while recovering from a broken arm, is scheduled to pitch on Tuesday. It will be his second start and he is scheduled to pitch three innings.
• Colby Lewis, who is recovering from flexor tendon surgery in his right elbow, is scheduled to pitch on Saturday. He pitched one inning without problem in his first extended spring start on Monday. The Rangers are planning on him throwing two innings on Saturday. The Rangers will then decide if Lewis needs to stay in extended spring or be sent out on a medical rehabilitation assignment somewhere in the Minor Leagues. Once Lewis goes on rehab assignment, he has 30 days before he has to be activated off the disabled list.
• Kyle McClellan, who is still in extended spring workouts because of a strained rib cage muscle, is throwing off the mound in the bullpen. Joakim Soria, whose comeback has been delayed by a strained chest muscle, has not resumed throwing.
• Relief pitcher Joseph Ortiz has asked that he be referred to by his full first name.
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.