According to David O'Brien of The Athletic
, during the latter stages of summer camp, O'Brien was exposed to someone who tested positive for COVID-19, derailing any hope he had of cracking the Braves' season-opening 30-man roster. Though O'Brien has presumably cleared all COVID-19-related protocols, the Braves evidently determined he wasn't worth keeping around at their alternate training site in Gwinnett. The Braves added 2020 fourth-round pick Spencer Strider
to the 60-man roster pool in a corresponding move.