NEW YORK -- The Rangers named Jerome Williams as their starter for Friday's game against the Oakland A's. The club will make a corresponding roster move Friday to clear a spot for Williams.

Williams was 0-1 with a 6.10 ERA for Triple-A Round Rock. In his last start July 18 vs. Iowa, he allowed four runs on nine hits in six innings of work with three strikeouts in a loss. Opponents are hitting .348 against him with three home runs in 10 1/3 innings.

The move was necessary after the club deemed Nick Tepesch wouldn't be able to start Friday after being used as an emergency reliever in Tuesday night's 14-inning loss to the Yankees.

"We got to keep what we got in the bullpen," manager Ron Washington said. "We signed him (Williams) and take a look at him and he's ready to go."

The Rangers didn't want to insert a reliever into a spot-starting situation. Scott Baker had also been considered a possibility.

Williams was signed by the Rangers on July 11 and assigned to Round Rock after he was released by the Houston Astros. He was 1-4 with a 6.04 ERA as a reliever this season for Houston. In his career, Williams is 43-51 with a 4.45 ERA. His last start came against the Rangers while he was pitching for the Los Angeles Angels in September of 2012. He lost a 6-5 decision.

"He's a (right-hander), can sink the ball pretty good and he can run it in on right-handers, got a good breaking ball and we'll see what he has to offer," Washington said.

The scheduled starters for the weekend will be Tepesch on Saturday and Miles Mikolas on Sunday. Yu Darvish is on target to pitch against the New York Yankees on Monday.