Vrana agreed to terms on a professional tryout agreement with Washington on Thursday.
Vrana saw action in 21 games for the Blues last year in which he notched two goals on 42 shots, four assists and nine hits while averaging 12:08 of ice time. The 28-year-old winger spent parts of five seasons with the Capitals, including the club's Stanley Cup-winning 2017-18 campaign. Heading into the upcoming season, Vrana will likely need to edge out the likes of Michael Sgarbossa or Sonny Milano to secure a permanent NHL deal -- though a two-way contract could also be an option for the Caps if Vrana is willing to go that route.