"The surgery went well enough that there's some hope that potentially he could pitch next year, later on in the season," A's manager Bob Melvin said. "From the beginning, hearing about where this thing could go, we've anticipated him being out for the entire season, but we'll leave a ray of hope that potentially he could come back sometime next year."
A's head trainer Nick Paparesta, however, hesitated to say as much, instead wishing to focus on the road ahead rather than the end.
"There's no timeline," Paparesta said. "I think putting a timeline and saying, 'He's going to be back in X amount of days or months' is unfair to Sean, it's unfair to the surgeon and the rehab process that's ahead of him. I think Sean's in a great place. I think he's getting ready to start his rehab on Monday and have a good, strong rehabilitation season, and we'll see where we are at the beginning of Spring Training.
"Once we get to Spring Training, we'll have a good timeline, we'll see if he's hit all of his markers and we'll have more information at that point."
Per the A's, Dr. Neal ElAttrache performed a subacromial decompression, acromioplasty and posterior labral repair at the Cedars-Sinai Kerlan-Jobe Institute in Los Angeles. In short, he created more room within Manaea's joint capsule and repaired his labrum.
"I think in talking to Dr. ElAttrache yesterday, that this was probably the best-case scenario for him and his shoulder surgery," Paparesta said. "We all are very confident, and Dr. ElAttrache echoed that to me on the phone. He was very encouraged and very excited about how things went, and we all feel that Sean will be back at the Major League level competing again."
Manaea, Paparesta said, was dealing with chronic shoulder impingement for two years, worsening to the point where he couldn't pitch without pain. The 26-year-old lefty was 12-9 with a 3.59 ERA in 27 starts this season, twirling a no-hitter against the Red Sox on April 21.
"We tried some conservative measures over the last three weeks to see if Sean could pitch again this season," Paparesta said. "It wasn't possible, so we determined it was time to go ahead and proceed with surgery."
• Right-hander Trevor Cahill, who has missed two starts because of upper back discomfort, is expected to return to the mound Sunday against the Twins. Reliever Liam Hendriks will open Friday's game, with Mike Fiers getting the nod Saturday.
• Utility man Chad Pinder was presented the 2018 Dave Stewart Community Service Award by Stewart himself prior to Thursday's game.
Pinder has teamed up with the School of Imagination and supports several A's community initiatives, including fundraising events and hospital visits.
Jane Lee has covered the A's for MLB.com since 2010. Follow her on Twitter @JaneMLB.