Since being acquired by the A's on July 5, Jason Hammel hasn't dominated the opposition the way he did as a member of the Cubs in the season's first half. In his first two starts in green in gold, Hammel has gone 0-2 and allowed eight runs (seven earned) over seven innings.
Hammel surrendered five runs on six hits over two-plus innings in his last outing, against the Orioles on Saturday.
When the A's open a three-game set against the Rangers in Arlington on Friday night, Hammel will try to rediscover the form that brought him so much success earlier this year. The veteran right-hander went 8-5 with a 2.98 ERA as a Cub this season, striking out 104 batters and walking 23 in 108 2/3 innings.
"I'm not pitching like myself right now," Hammel said. "I need to get back into what I do well, and that's fastball command and harnessing the slider."
Nick Tepesch was scheduled to start the series opener for Texas, but after the right-hander was forced to appear in relief during a 14-inning loss to the Yankees on Tuesday, manager Ron Washington opted to scratch him.
Tepesch took the loss when he surrendered a walk-off single to newly acquired Yankee Chase Headley in the bottom of the 14th inning. He threw only 12 pitches during the contest, but he also threw a bullpen session earlier in the day, so Washington decided to make a change for Friday as a precautionary measure.
"He's a young kid and we had to push him in an unusual situation, so it wasn't necessary to push him [more]," Washington said of Tepesch.
Triple-A Round Rock right-hander Jerome Williams will start in place of Tepesch. The Rangers signed Williams on July 11 after the Astros released him. Texas will make a corresponding roster move on Friday to clear space.
"I know Jerome Williams -- faced him enough," Washington said, alluding to Williams' three years with the Angels. "When he's right, he can sink the ball pretty good. He can run it in on right-handers and has got a good breaking ball. So we'll see what he has to offer."
A's: Struggling Johnson designated
Veteran reliever Jim Johnson was designated for assignment on Thursday morning, marking the end of a tough eight-month tenure in Oakland.
The former closer, relieved of his ninth-inning duties just two weeks into the season, posted a 6.92 ERA with Oakland and faces an uncertain future. Johnson should clear waivers because of his hefty price tag -- he's earning $10 million this season -- and is likely to be released.
Even if he were to be offered a Minor League assignment, an improbable proposition, Johnson has enough service time to decline it and become a free agent.
Either way, his time with the A's organization is considered over.
"It started out bad for him, and he just couldn't get into a spot where he could find himself and not have to think about some of the failures," said manager Bob Melvin. "It just kept snowballing on him.
"A lot of times, when you get dug into a hole like this, maybe the best thing for him is a breath of fresh air. It wouldn't surprise me if somebody picked him up and he started to pitch much better."
Rangers: Rios awaiting fate
Texas has already dealt reliever Joakim Soria, and now, outfielder Alex Rios waits to see if the Rangers will trade him before the July 31 non-waiver Trade Deadline.
Rios is signed through this season, but the Rangers have a $12.5 million option on him for 2015. The Yankees are among the teams looking for offensive help. But if the Rangers do trade Rios, they could be hard-pressed to find somebody to play right field next season.
"I'd rather not say anything about that right now," Rios said. "I'm focused on what I have to do until something actually happens."
• Neftali Feliz is taking over as Rangers' closer, but he said he would miss Soria, who was traded to the Tigers on Wednesday night. Both pitchers underwent Tommy John surgery in 2012, and Soria helped guide Feliz through the recovery process.
"Soria was a great teammate," Feliz said. "He gave me great advice going through rehab. He consulted me on a lot of things."
• The A's have 10 wins when trailing after seven innings, which is tops in the Majors and tied for second most in Oakland history.