OAKLAND -- Frustration got the best of Drew Pomeranz, who has landed on the disabled list with a fractured right hand after punching a wooden chair following Monday's disappointing outing.

The lefty was on his way up to the clubhouse Monday night when hand met chair.

"I just let my emotions take over me, and I did something stupid," Pomeranz said Tuesday afternoon. "Obviously, I didn't mean for it to happen. It sucks because I want to play, I want to pitch. I'm trying to win games and help the team out. Obviously, I'm not helping the team out when I do something stupid like that."

"It's disappointing," said manager Bob Melvin. "It affects how we go about our business here. He's a guy that's done really well for us. He feels horrible about it. I know it wasn't intentional, it was out of frustration, but you've also got to realize that there are ramifications when you do something like that, and he's realizing that now."

Pomeranz endured the worst start of his career Monday night, allowing the Rangers eight runs (seven earned) on eight hits and two walks in just 3 2/3 innings. He had surrendered just eight runs total in his previous seven starts spanning 38 1/3 innings.

The southpaw will be able to continue throwing while his other hand heals, but "whenever I can catch a ball again is whenever I can pitch again," he said.

There's no timetable for his return, and the A's will be in need of a replacement starter come Saturday. Melvin strongly suggested it would be lefty Brad Mills, acquired by Oakland from the Brewers for cash on Tuesday morning, but also named Triple-A righties Dan Straily and Arnold Leon as candidates, too.

Mills, who will report to Triple-A Sacramento, was 4-2 with a 1.56 ERA and .190 opponents average in 14 games, including 12 starts, with Triple-A Nashville.

"Hopefully, I'll be back as soon as possible," said Pomeranz. "This is the first time I've broken a bone, though, so I don't know.

"I play it over and over in my head -- wish I hadn't done it. I was walking up to the clubhouse and was just mad."

Right-handed reliever Evan Scribner was called up from Triple-A to take Pomeranz's roster spot.