The Athletics released Guerra on Aug. 5.
Signed to a minor-league deal this past season, Guerra spent the first half of the 2023 campaign completing his recovery from April 2022 Tommy John surgery. He began a rehab assignment in the rookie-level Arizona Complex League in late June before returning from Triple-A Las Vegas' 60-day injured list in early July. He made just three appearances for Las Vegas before returning to the 7-day IL on July 17 and then being cut loose three weeks later. The 34-year-old reliever has previously made 134 MLB appearances, but none since 2021.