Cahill ready for return

HOUSTON — Trevor Cahill will be back in action for the final game of the series Thursday, and the right-hander said his injured Achilles tendon was tested in his four-inning rehab start Saturday, so he knows he’s sound.

“I feel good, the Achilles is completely fine,” said Cahill, who missed a month with a right Achilles strain. “In my rehab start, I jumped off the mound for a chopper, ran to first. No problem.”

Cahill was enjoying success before he was injured; he has a 2.77 ERA in eight starts, lowest among the team’s starters. He went on the disabled list, for the second time this season, during a stretch in which the team has had as many as six starters out of action.

“That was unfortunate,” manager Bob Melvin said. “He was pitching probably as well as he was when he was last here (2009-11). He’s come up with some other pitches and different ways to do things. At the time, that hurt us . ... It’s nice to have him come back, certainly with the way he’s been pitched for us this year. Starting to get guys back as opposed to losing them is a better trend.”

Cahill has faced the Astros once this year, going six innings and allowing four hits and four runs, three earned; he walked one and struck out five. And pitching last in a four-game series can be helpful — if a little frustrating.

“I was just thinking about that,” he said. “The first game of a series is kind of tough because you don’t know how well the other team is playing, how aggressive they might be. But when you’re fourth, it seems like a long time — it feels like we’ve been here forever.”

The A’s will have to make a move to get Cahill on the roster; Chris Bassitt is likely to be sent down to keep getting work during the break but could return in some role after the break. Briefly: First baseman Matt Olson was out of the lineup with minor back tightness but entered in the fifth after Stephen Piscotty departed after getting hit by a pitch. Olson, who has played in every game this season, went 0-for-2 . ... Oakland made one international signing recently, Cuban catcher Marcos Betancourt, who went 0-for-2 with the A’s Dominican Summer League team Wednesday.