Kuo, on an amended game schedule to protect his brittle elbow, came out of the workout pleased and healthy.
Pitching coach Rick Honeycutt said Kuo has been working on a changeup for years but has used it sparingly in games so far. It would be a nasty complement to his fastball and hard slider, said Honeycutt.
Kuo pitched only two game innings last spring before coming up with a sore elbow. He made his first game appearance Wednesday.