Arnaud, 25, comes to the Redskins from the Saints, where he signed in February 2001 after spending the 2000 season as a member of the Baltimore Ravens practice squad.
Arnaud began his career in the NFL as an undrafted free agent with the Ravens, signing in April 2000. A 5-11, 210-pound product of Georgia, he carried the ball 90 times for 330 yards (3.7 avg.) and three touchdowns during his four-year collegiate career.
The Redskins also announced they have released wide receiver Tyrone Goodson.