Fernandez, 33, posted a career-worst 6.40 ERA and had a 1-8 record in 15 starts last season for the Mariners. The six-time All-Star, two-time ERA title winner and 2010 Cy Young Award winner has a 3.42 ERA and 169-136 record during his decorated MLB career.
He had a $27.8 million salary with the Mariners last season.
Hernandez has been plagued with a number of injuries over the last several seasons. He briefly moved into the Mariners' bullpen in 2018 after missing time because of shoulder issues.
The Braves are searching for a fifth starter in their rotation behind Mike Soroka, Max Fried, Mike Foltynewicz and Cole Hamels. Braves pitchers and catchers have their first workout Feb. 13.