UPDATE (12:44 pm PDT on Saturday): The A's officially recalled right-handed pitcher Daniel Mengden from Triple-A Nashville on Saturday afternoon.
***
OAKLAND - The A's made a call to the minors for a starter Saturday, but their selection is quite familiar to the major league club.
Daniel Mengden will be recalled from Nashville and take the ball against Boston on Saturday night. The right-hander with the handlebar mustache and eye-catching delivery had an excellent start to his big league career, piling up 26 strikeouts with a 2.81 ERA over four starts after being promoted in early June.
He found the going rougher in July and the A's, noticing diminished velocity, sent him to Triple-A and cut down on his pitch counts. Mengden responded by going 5-1 with a 2.10 ERA in six starts after being sent down.
"He really got our attention early on," A's manager Bob Melvin said. "We felt like when we sent him down he was just a little tired. We cut down on his workload, he's been pitching great since, so it's nice to have him back."
[RELATED: A's reinstate Doolittle, send Hahn to Triple-A; recall McBride]
Oakland Athletics
Expect more pitching reinforcements from Nashville to arrive as September unfolds. But that may not include Jesse Hahn, who was activated from the 15-day disabled list and optioned to Nashville on Friday. Hahn, who's been on a rehab assignment with Nashville for a strained shoulder, gave up seven runs on 11 hits Wednesday against Iowa.
"Jesse had a little bit of a struggle in his last game, so we'll have him pitch a little bit more down there," Melvin said. "It's been a tough year for him. …We still feel like he has a bright future here."
Asked if Hahn could be called up after a couple more Triple-A starts, Melvin said: "We'll see. We have some other guys we'll probably take a look at too here in the interim."
Jharel Cotton and Raul Alcantara are the two most likely starters to get the call from Triple-A, but Melvin said the A's will be mindful of not draining too much talent from Nashville as the Sounds gear up for the PCL playoffs.
Catcher Matt McBride was the only minor leaguer called up Friday. Rosters can now expand from 25 to a maximum of 40.
"You might see some of the starting pitchers before we add some position players," Melvin said. "But it always is a balance. You want to give your Triple-A team the best chance to win, even though guys want to be here."
**
Reliever Sean Doolittle rejoined the active roster after being sidelined since late June with a shoulder strain. Since that time, franchise cornerstones Coco Crisp and Josh Reddick have been traded.
"It's really weird," Doolittle said. "Me, Sogey (Eric Sogard) and (Jarrod) Parker are the only three remaining guys from 2012. … It was definitely different walking around the clubhouse today."
Doolittle said the extra couple minor league appearances he made were necessary and got him better prepared to face big league hitters. His fastball previously was clocking 89-91 miles per hour but has improved to 93-94, and the result has been more swings and misses and better deception with his fastball.
"The mechanics part just kind of clicked as well," he said. "Everything fell back into sync. I just felt more like myself the last couple outings."
**
Sean Manaea, who left Monday's start with a strained back muscle, played catch Friday but his next start has yet to be determined.
**
Henderson Alvarez is set for another rehab start with Single-A Stockton on Saturday, and it seems he could be on track to join the A's in a relief role before the season ends. He has yet to pitch for Oakland due to complications from shoulder surgery.
