San Francisco Giants right-hander Justin Verlander threw during a bullpen session on Tuesday night as the 42-year-old, three-time Cy Young Award winner tries to work his way back from a strained right pectoral muscle. Verlander wore road-gray uniform pants and a black, short-sleeve crew neck as he threw from the mound in the bullpen at Detroit's Comerica Park, where the Giants played the second of a three-game series with the Tigers, losing 3-1. Verlander struggled with velocity and command because of discomfort during his most recent start on May 18 against the Athletics, a game which he left after four innings.