Castro allowed one hit and struck out one over a scoreless two-thirds of an inning to record the save in Friday's 7-5 win over the Giants.
Castro got the call from the bullpen after Andrew Chafin got the first out of the ninth inning. It was Castro's second save of the season. Chafin has been the primary closer, but manager Torey Lovullo had him enter the eighth inning against a string of lefty batters. The sequence hinted at changes Lovullo mused about with Theo Mackie of the Arizona Republic. In reaction to a string of adverse relief work, the manager talked about shifting roles and avoiding the overuse of his most trusted arms, like Chafin.