The Brewers optioned Dunn to Triple-A Nashville on Thursday.
Dunn has started at third base all 11 times the Brewers have faced a right-handed pitcher this season, but he'll head back to the minors after slashing just .167/.205/.222 across 41 plate appearances. The Brewers have not announced a corresponding roster move, but they could recall Caleb Durbin from Nashville to take over as their primary option at the hot corner.