The contract includes a team option for the 2024 season.
The Braves acquired the 30-year-old Rosario from Cleveland before last season's trading deadline. He hit .271 with 13 extra-base hits, including seven home runs during the regular season.
But he took things to another level in the postseason, hitting .560 with three home runs and and nine RBIs in the National League Championship Series en route to being named the MVP of the series. Overall, in 16 playoff games, he hit .383 with seven extra-base hits to help the Braves win a World Series championship. He also had an 11-game hitting streak in the postseason, tied for third longest in Braves playoff history.
For his career, Rosario has a .275 average with 133 home runs and 450 RBIs.
Dickerson, 31, hit .233 with 13 home runs and 38 RBIs for the San Francisco Giants last season.
Thornburg, 33, last pitched in the 2020 season for the Cincinnati Reds when he appeared in seven games before a right elbow sprain landed him on the injured list. He underwent Tommy John surgery in September of that year and missed the entire 2021 season.