Hall went down after colliding with a teammate trying to make a tackle in the second quarter. He said Redskins doctors, including James Andrews, told him "it kind of feels like you tore your ACL." Tests confirmed the injury.
Hall turns 33 years old in November and is owed $5 million in 2017. After spending his first seven seasons in Washington as a cornerback, Hall shifted to safety last season.
It's the second time in three seasons Hall suffered a season-ending injury. In 2014, he ruptured his Achilles.