The Athletics optioned Serven to Triple-A Las Vegas on Wednesday, Jason Burke of Roundtable.io reports.
After coming up from Triple-A to bolster the Athletics' bench depth for the final weekend before the All-Star break, Serven will now return to Las Vegas to begin the second half. The 31-year-old backstop is likely to spend most of what's left of the season in the minors, where he's slashing .308/.403/.525 across 236 plate appearances.