Marcus Semien balances fatherhood and playing ball

Marcus Semien misses newborn son Isaiah, born on Monday

Marcus Semien plays with single mindedness of purpose, one of the characteristics the A’s most like about their shortstop.

Things have been a little different for him this week, though. He rejoined the team Friday in St. Louis after missing a three-game series against the Indians to be with his wife, Tarah, at the birth of their first child, son Isaiah.

Like many first-time fathers, he’s torn between being with his family and being with his team.

“Just about any time I’m not at the park I’m on FaceTime with them,’’ Semien said Monday. “It sucks to miss this time of his life.

“It’s been four days already, and I’ve missed a high percentage of his time.’’

That time away is something many players go through, and Semien, who hadn’t missed a game all year for Oakland before taking three days and eventually going on paternity leave, is learning that the hard way.

The A’s will be home Wednesday night and start a 10-game homestand, so there will be some time for caching up.

“I spent the first couple of nights in the hospital with them,’’ Semien said. “I miss that.’’

–No part of the A’s has been more in flux than the starting rotation, and with the rosters eligible to expand from 25 players to 40 beginning this weekend, the rotation roulette may not yet be over.

Manager Bob Melvin said no decision has been made on what to do with the rotation for the final month of the season, but with Oakland currently having three relievers – Andrew Triggs, Zach Neal and Ross Detwiler – filling in thanks to injury repletion, there are minor league starters the club could bring up.

Of them, one who immediately piqued Melvin’s interest was Jharel Cotton, who came within one out of a perfect game in his second start for Triple-A Nashville after the A’s acquired him in the trade of Josh Reddick and Rich Hill. Since joining the Sounds, Cotton is 3-1 with a 3.31 ERA.

The manager also mentioned Raul Alcantara, who is 4-0 with a 0.89 in seven starts for Nashville after being promoted from Double-A, and Daniel Mengden, who has struggled in nine starts with the A’s, going 1-5 with a 5.73 ERA but who is 8-2 with a 1.67 ERA with the Sounds.

NOTES

–The new timetable for reliever Sean Doolittle is for him to rejoin the A’s on Friday when the Red Sox visit the Coliseum. The lefty, out since June 26 with shoulder trouble, will throw in a game Tuesday with Nashville as a final tuneup before coming off the disabled list.

–Billy Butler passed the last of his concussion protocol tests Sunday in St. Louis and was activated by the A’s Monday. He and the A’s say he’s good to go, although he wasn’t in the starting lineup against the Astros.

–Henderson Alvarez (shoulder surgery) will pitch Tuesday with Class-A Stockton in his ongoing bid to get back with the A’s before the season’s over.

–Jesse Hahn, on a rehab assignment with right shoulder strain, is due to start Wednesday for Stockton, after which he’s expected to be cleared to return to the rotation.

–Sonny Gray played catch Sunday for the first time since landing on the disabled list on Aug. 7 with a strained right forearm. His strengthening exercises have been going well, so much so that manager Bob Melvin now believes having Gray return to the club to pitch this season is at least possible.

–Catcher Josh Phegley, hospitalized since Friday with synovitis in his right knee, is due to get out of the hospital Tuesday. It’s a complication from the surgery in the knee he had midseason. The A’s had hoped he’d be available for the final month of the season but they now believe it’s unlikely he will catch for them again this season.