Peterson ran for 1,042 yards and seven touchdowns with Washington in 2018. He took over as the team's starting running back after Derrius Guice suffered a season-ending torn ACL in August.
Guice will likely be Washington's preferred No. 1 option on the ground next season.
The team selected him in the second round of the 2018 draft after he ran for 3,074 yards and 29 touchdowns in three years at LSU. He figures to be a big part of the offense going forward.
Peterson would provide a level of insurance, though, should Guice struggle early on with any lingering effects from his knee injury. The 12-year veteran averaged 4.2 yards per carry and finished 29th among qualified running backs in DYAR (defense-adjusted yards above replacement), per Football Outsiders.
Because of Guice, Washington won't want to invest significantly in the running back position in free agency. The team only has $20.1 million to spend as well, per Over The Cap, and that money would be better spent on another area.
By bringing Peterson back for 2019, Washington would have a solid backup option at what's likely to be a reasonable price. Peterson earned a $1 million base salary this past season, and it's hard to see him getting much more than that considering he turns 34 in March.