"That's my expectation," general manager Jon Daniels said. "We'll know more when he throws this weekend. He has shown some improvement so we're hoping he can start on Monday."
Gonzalez was called up to fill in for Hamels, who was originally scheduled to pitch on Thursday. The Rangers were forced to make a roster move and they wanted to keep their bullpen intact. By sending down Martinez, that means Gonzalez has a chance to remain in the rotation for more than one start.
Martinez was optioned after allowing seven runs, four earned, in 3 2/3 innings against the Twins on Wednesday. He is 7-7 with a 4.09 ERA after 21 starts for the Rangers.
"We still view him as a promising young starter," Daniels said. "The big leagues are hard. It's hard to go wire to wire. We need him in the future. We'll need him this year."
The moves also suggest there is a spot for Derek Holland in the rotation when he comes off the disabled list. Holland is on the disabled list with a strained muscle in his left shoulder and is scheduled to make his fourth start on medical rehabilitation assignment on Friday for Round Rock. Daniels suggested he'll likely need at least one more start after that.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.