Washington's backfield is riddled with injuries. The team lost rookie Derrius Guice to a season-ending ACL tear in Week 1 of the preseason, while Samaje Perine and Byron Marshall are on the shelf with short-term ailments.
Charles, 31, spent last season with the Denver Broncos following his nine-year stint with the Kansas City Chiefs. The four-time Pro Bowler produced 296 yards and a touchdown on the ground for Denver last season in a limited role.
Charles posted five 1,000-yard rushing seasons from 2009-14, but significant knee injuries in 2011, 2015, and 2016 have diminished his athletic abilities.