Graterol struck out one batter in a perfect inning against Arizona on Thursday.
Graterol missed over three weeks due to an elbow issue before he was activated Thursday. The right-hander was immediately given high-leverage work when he was called upon in the eighth inning with the score tied 1-1. Graterol threw 12 strikes among his 16 pitches and retired the side in order. He could be a key factor down the stretch and in the playoffs with Craig Kimbrel possibly losing his hold on the closer role and Blake Treinen's status uncertain due to a shoulder injury.