Dodgers pitcher Zack Greinke threw a 25-pitch bullpen session Thursday as he recovers from a mild right calf strain. Manager Don Mattingly said Greinke might next throw to hitters, which would put him on track for an exhibition game start next week. Greinke is not expected to make the Dodgers' season-opening trip to Australia. Greinke, who was injured four pitches into his first start a week ago, made his first 20 throws Thursday out of the stretch and the last five from a windup. He threw fastballs and breaking balls.