Selman was optioned to Triple-A Las Vegas on Saturday.
Selman was brought up by the A's earlier in the week, but he will head back to the minors with fellow pitcher Kirby Snead rejoining the roster. Selman struck out five batters while tossing 2.2 scoreless innings in Friday's loss to the Rangers, so he should garner consideration next time the A's need to add a reliever to the roster.