"I feel good, my hand feels good," Gentry said. "It doesn't bother me when I swing."
Gentry spent the first 2 1/2 months of the season platooning with Leonys Martin in center field. Martin, a left-handed hitter, has been playing regularly since Gentry went down. Manager Ron Washington said Gentry will start playing against left-handers but he's not sure if he'll go back to a platoon situation.
"Martin has been playing against lefties, but I'm going to pick and choose," Washington said.
Baker has been playing mainly against left-handers and was doing serious damage against them before a right thumb sprain. Baker, who hasn't played since June 12, was hitting .386 (17-for-44) with eight home runs against left-handers. He was 2-for-11 overall in three games with Frisco and is expected to be in the lineup on Friday against Orioles left-hander Wei-Yin Chen.
"There are no issues, I'm good to go," Baker said.
To make room on the active roster, the Rangers optioned catcher Robinson Chirinos and right-handed reliever Wilmer Font.
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.