The Athletics optioned Basso to Triple-A Las Vegas on Wednesday.
Basso was up in the majors for just one day and didn't make an appearance. The left-hander could still be needed in the Athletics rotation at some point given the big club's mounting injury list, but for now he'll report to Las Vegas. Basso was torched for nine earned runs over 2.1 innings in his lone start with Las Vegas this season but has put up a 2.84 ERA and 32:3 K:BB over 25.1 frames with Double-A Midland.