The Athletics designated Stefanic for assignment Saturday.
Stefanic will be pushed off the Athletics' 26- and 40-man rosters following the team's acquisition of Alika Williams from Pittsburgh on Saturday. Stefanic went 2-for-5 with a run scored during his four-day stint in the majors and owns a .706 OPS through 149 plate appearances at Triple-A Las Vegas. He'll likely spend the rest of the season as organizational depth if he clears waivers.