The Reds placed Dunn on the 10-day injured list Sunday due to a right elbow sprain.
Dunn was sent in for an MRI on Saturday after being lifted from Friday's 6-4 win over the Pirates due to elbow discomfort, and though the severity of the injury isn't yet known, he's been diagnosed with a sprain and will remain out until at least July 7. Cincinnati recalled TJ Friedl from Triple-A Louisville in a corresponding move, but it's unclear if he'll be deployed in the strong side of a platoon in center field in Dunn's stead, or if Dane Myers will step in as the preferred option at the position against both righties and lefties. Noelvi Marte has also made two starts in center field this season but is more ideally suited for a corner-outfield spot.