Stars GM Jim Nill and head coach Lindy Ruff announced the moves Monday.
Stars defenseman Brandon Saadi is a restricted free agent and has a no-movement clause in his contract, according to the league office.
The Stars signed forward Jonathan Dribin on Sunday and forward Jakub Voracek on Monday.
Saad, a 6-foot-5, 220-pound defenseman, had four goals and six assists for 14 points in 36 games last season.
The 23-year-old is a free agent after the season and could receive a second contract if he plays well.
He also has a $3.75 million cap hit next season.
Dubinsky, 25, had three goals and four assists for six points in 34 games last year.
The 23-old has a cap hit of $1.5 million.
The Dallas Stars have three unrestricted free agents: center Ryan Garbutt (signed last week), forward Trevor Daley (signed Monday) and defenseman Andrew Mangiapane (signed Tuesday).