MESA, Ariz. -- Yu Darvish was scratched from his Cubs debut on Thursday against the Rockies because he was still feeling a little ill, but he did get his work done during a bullpen session instead.
"He's not horribly ill, but he's had this thing with his stomach," Cubs manager Joe Maddon said of the right-hander. "We're concerned about dehydration. If he goes out there [in a game] and pitches and sweats a little bit and pulls something, that's not smart."
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Darvish, who signed a six-year contract with the Cubs on Feb. 13, has been bothered by the stomach flu for a few days. He told Maddon that he didn't think he was ready for a game.
"We decided it's much better to do it this way," Maddon said. "There's no hurry, and he felt really good about it."
Darvish, projected to start the Cubs' third game of the regular season, will stay on schedule and is expected to make his Cactus League debut next Tuesday against his former team, the Dodgers.

Right-hander Alec Mills, who was named the Cubs' starter Thursday against Colorado, worked two shutout innings with three strikeouts and a walk.