Garner has been ruled out for the 2018 season after suffering an ACL tear in Thursday's preseason opener, Adam Schefter of ESPN reports.
Garner received a promotion from Washington's practice squad last December after failing to make the roster out of camp, but he failed to appear in a game for the Redskins. His pursuit of a 53-man job out of camp this season just hit a major snag, and he will now have to wait until 2019 to take another shot.