Hamels, 37, is not planning on retiring after a mostly lost 2020 season due to shoulder and triceps injuries. He made one start with the Atlanta Braves when he allowed three earned runs over 3 1/3 innings of work.
The Giants are looking to add a left-handed starter, general manager Scott Harris told Morosi on Tuesday. The club currently projects to have five righties - Johnny Cueto, Kevin Gausman, Anthony DeSclafani, Logan Webb, and Shaun Anderson - in the rotation.
Before joining the Braves on a one-year deal last offseason, the four-time All-Star made 39 starts with the Chicago Cubs. He went 11-10 with a 3.30 ERA, 1.30 WHIP, and 9.0 K/9 during his Cubs tenure.