Richards threw 25 pitches from the stretch and 25 from the windup in his fourth bullpen of the spring.
Richards said he was "knocking off some cobwebs early, as far as throwing the breaking ball," but otherwise felt great and would continue to make progress.
Richards was 13-4 with a 2.61 earned-run average last season before he suffered a ruptured tendon in his left knee while covering first base against the
He reiterated that his goal was to be ready by opening day, and that his leg was fine.
"I would say my mechanics are tighter now than they've ever been," he said. "Whether that's because I'm being more cautious in my delivery or just because I'm just focused on throwing a quality bullpen, I don't know.