Dunn, whose next scheduled turn in the rotation would normally come Tuesday, will instead start Wednesday against the Dodgers, Daniel Kramer of MLB.com reports.
The young right-hander will flip spots with Yusei Kikuchi on a temporary basis, with manager Scott Servais calculating the latter is a better bet to require fewer innings out of his bullpen. Dunn has pitched to an impressive 3.51 ERA and serviceable 1.29 WHIP through his first five starts, but he's yet to go deeper than 5.2 innings in any of those outings.