Head coach Mike McDaniel told reporters Friday that Johnson tore his ACL in Thursday's practice, David Furones of the South Florida Sun Sentinel reports.
The 25-year-old appeared in four games prior to tearing his ACL, recording three total tackles across 58 total snaps (55 on special teams, three on special teams). With Johnson now sidelined, Ethan Robinson is expected to operate as the Dolphins' top reserve slot corner.