"He had flashes," general manager Jon Daniels said. "He had one very good start at the beginning of the year against the Angels. He won a big game out there. He never seemed right in the middle of the season. His command was never where it needed to be. Hopefully this will help him going forward."
Daniels said Gabbard is still in the club's long-term plans.
"In one role or another, starter or bullpen, he'll factor in for us next year," Daniels said.
Texas' pitching staff has been ravaged by injuries this season. Joaquin Benoit, Doug Mathis, A.J. Murray and John Rheinecker are all on the DL and at extended spring camp in Arizona.
Benoit threw on Friday and will have a bullpen session soon, according to Daniels.
Jason Jennings is also out for the season.
Vicente Padilla and Eric Hurley are on the DL, but will be activated for starts on Sunday and Monday, respectively.
Brandon McCarthy, on the DL since March 30 with right forearm inflammation, will begin a rehab assignment on Tuesday with Triple-A Oklahoma. The right-hander will pitch a maximum of four innings or 60 pitches.
Thor Nystrom is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.