CHICAGO -- A's starter Jharel Cotton , cruising his way through the White Sox lineup, was forced out of Friday's 3-0 series-opening win in the sixth inning because of a right thumb blister.

Shortstop Chad Pinder also left the game prematurely with a left hamstring strain, departing after five innings, and could potentially be out of the lineup for a while.

The A's found solace in their consolation prize -- a win on the road, just their 10th of the season in 35 away games this season -- and in news that Cotton's blister may be minor enough to keep him on track for his next start.

"It doesn't seem to be a big issue as far as blisters go," A's manager Bob Melvin said.

Cotton was five-plus innings into what was shaping up to be one of the best starts of his season when Melvin and a team trainer emerged from the visitor's dugout. Melvin took one look at Cotton's thumb and motioned for bullpen help.

"It was a little more humid tonight, and I was spinning my breaking balls as usual, and it just started to create a blister from the second to the fifth inning," said Cotton, who has dealt with a blister in a different location on the same thumb this year. "During the sixth, it just popped open and it was bleeding, so the manager came out and said that was it, good job kid."

The right-hander had just yielded his third hit of the night, a lead-off single to Kevan Smith , before departing in favor of right-hander Liam Hendriks .

Cotton, who had a 5.02 ERA in his five previous starts since returning from Triple-A Nashville, walked one and struck out three in the shortened outing. He threw 66 pitches -- 42 strikes -- and flashed impressive command along the way.

"We've seen him really good and we've seen him struggle with command, and today, for the most part, command wasn't an issue," Melvin said. "When he's throwing the ball where he wants to and he's using all his pitches, he usually has some success."

Pinder, meanwhile, felt discomfort in his hamstring beginning in the second inning. It escalated in the fifth, when, with two outs, he tried to snag a bouncer up the middle off the bat of Yolmer Sanchez . The ball bounced off his glove and, while looking down, almost contemplating the play, Sanchez attempted to take second, but Pinder tossed the ball to second baseman Jed Lowrie in time for an out that was upheld on replay.

"I really started to feel it laterally, especially with that ball up the middle," Pinder said. "That's no excuse. I still gotta be in that play, and luckily we got him out at second base. Once the adrenaline wore off from that play, it started to really, really bark, so at that point, we thought it was best to get it checked out."

"Usually those things aren't one day," Melvin said. "It's going to be day to day as we speak right now. We'll probably have a better idea tomorrow."