Bridwell has been diagnosed with a broken rib and is expected to miss 4-to-6 weeks, Jon Meoli of the Baltimore Sun reports.
The young right-hander was already placed on the 7-day DL earlier Thursday, but Orioles manager Buck Showalter has since informed reporters of the nature and extent of the injury. The Orioles' No.8 prospect in their system will likely be out until early July.