According to Rosenthal, the deal is for two years and includes a team option for a third year.
Grilli, 38, had played for the Pittsburgh Pirates since 2011 but was traded in June to the Los Angeles Angels after recording a 4.87 ERA in 22 games to start the season. He pitched better for the Angels, finishing the year with a combined 1-5 record and 4.00 ERA.
In his first MLB season as a closer, Grilli was an All-Star for the Pirates in 2013, recording 33 saves and a 2.70 ERA. He was demoted from the role in favor of Mark Melancon before being traded in 2014.
The Braves have significantly remade their roster this offseason, trading outfielder Jason Heyward and reliever Jordan Walden to the St. Louis Cardinals for pitchers Shelby Miller and Tyrell Jenkins and trading outfielder Justin Upton to the San Diego Padres for a four-player package.
Atlanta went 79-83 in 2014 and missed the playoffs for the first time since 2011.
- Ben Estes