Barnes (8-2) blew the save but picked up the win Sunday over Atlanta, allowing a solo home run in the sixth inning.
Barnes (3-2) was credited with the win Sunday over Atlanta, walking one and striking out one in a scoreless inning of relief.
The Nationals Andrew Golden of The Washington Post Barnes' contract from Triple-A Rochester on Tuesday.
Barnes signed a minor-league contract with the Nationals on Friday, Mark Zuckerman of MASNSports.com reports.
The Cardinals selected Barnes' contract from Triple-A Memphis on Tuesday.
Barnes was released by the Phillies on Monday.
Barnes signed a minor-league contract Tuesday with the Phillies, Matt Gelb of The Athletic reports.
Barnes was released by the Rangers on Sunday.
Barnes agreed Wednesday with the Rangers on a minor-league deal.
Barnes elected free agency Monday.