Rockies starter Aaron Cook, who has missed three days of pitching, will miss his first scheduled start of the spring because of continued setbacks from tightness in his shoulder and a bout with a stomach ailment. Colorado manager Jim Tracy said Thursday that Cook remains on a training program and that he will have to throw a bullpen session and likely throw live batting practice before he is cleared to pitch in an exhibition game. "He is getting stretched out to long distance and will eventually work his way back to the mound," Tracy said. "He had a couple of things he was battling early on and now he's progressing."