Fiers (elbow) suffered a setback during his rehab assignment and is unlikely to return this season, Martin Gallegos of MLB.com reports.

EDGE Analysis

Fiers appeared in three games at Triple-A Las Vegas over the past couple weeks, but he's been unable to reach his desired velocity and may make a visit to Dr. James Andrews, per Shayna Rubin of The San Jose Mercury News. The 36-year-old may not be available even if the A's manage a sustained playoff run.