The Rangers' pitching staff took another big hit Tuesday when it was determined that Alexi Ogando will be sidelined four to six weeks with a strained right groin muscle.
Ogando, placed on the 15-day disabled list, was to receive a blood platelet injection on Tuesday to help speed the recovery. He joins Neftali Feliz as two pitchers who will likely be unavailable until after the All-Star break.
"It was a little more significant than we expected," general manager Jon Daniels said of Ogando's injury. "We're looking at four to six weeks before he'll be back on a Major League mound."
The Rangers called up Michael Kirkman from Triple-A Round Rock. They have not announced a starter for Saturday against the Astros, but it will likely be either Kirkman or Robbie Ross.
"We're leaving it as TBA right now," Daniels said. "We've got a couple of options. We'll let it play out this week."
Roy Oswalt is scheduled to start for Double-A Frisco on Tuesday night. It will be his third start since signing with the Rangers as a free agent two weeks ago. The Rangers haven't decided when Oswalt will make his Major League debut, but he is scheduled to throw approximately 80 pitches for Frisco. It could be his last Minor League start or the Rangers could give him one more.
"We've said all along that he will start tonight and we'll re-evaluate it after that," Daniels said. "We want to make sure he is 100-percent ready from a standpoint of his arm and his conditioning."
Ogando was injured while beating out a bunt base hit in Sunday's game against the Giants. Ogando, who pitched three scoreless innings in the Rangers' 5-0 victory, was making a spot start for Derek Holland, who is also on the disabled list because of a stomach virus.
Holland and Feliz could both start a throwing program this weekend if they are cleared by Dr. Keith Meister. Holland would likely be back sooner than Feliz. He pitched last Tuesday against the Athletics. Feliz's last start was on May 18 against the Astros, and he would likely need several weeks to rebuild arm strength and endurance.
Daniels said the Rangers are not looking outside the organization for pitching help, knowing that at least Holland and Oswalt are one to two weeks away from being added to the Major League rotation.
"We're always considering our options," Daniels said. "We're probably a month away from the trade market heating up, but that's not where our mindset is. Our mindset is staying with what we've got, getting guys back and reassessing it."
Colby Lewis, Matt Harrison and Scott Feldman are scheduled to pitch in the three-game series against the D-backs that begins Tuesday. Yu Darvish will open the Astros series on Friday. Then it will be either Ross or Kirkman on Saturday. The Rangers don't seem intent on calling up Martin Perez from Round Rock.
Kirkman, who continues to undergo treatment for skin cancer, was 5-1 with a 5.25 ERA in 15 games at Round Rock. He was 4-0 with a 3.38 ERA in his last five starts and two relief appearances since May 6 while opponents hit .191 off him. He walked 19 and struck out 33 in 32 innings during that stretch.
"It's a fact of life, we were fortunate for the first two months that we didn't have any player moves while other clubs were dealing with more significant injuries," Daniels said. "We were fortunate, now we have to weather this storm. It's part of the reason we added Oswalt. You can't have enough pitching. If there is a silver lining, these guys get an unforeseen rest and maybe [it will] make them stronger in the second half."
That was not the Rangers' preferred plan.