"He's sick," Apodaca said. "He has some kind of stomach flu. He went to the hospital last night. He's not available at all."
Major League Baseball released a statement on behalf of the Giants shortly before game time confirming Lincecum would not be attending the game.
Lincecum's Giants teammate and fellow All-Star Brian Wilson said he hadn't spoken to Lincecum, whose phone was off.
"I think he caught the flu, so I think he's just getting some medicine for it," Wilson said.
While he could not attend the game, Lincecum was released from the hospital to rest.
His absence left the National League pitching staff one man short and manager Clint Hurdle of the Rockies with fewer options for the mound. The 24-year-old last pitched Sunday when he threw eight innings of one-run ball against the Cubs, meaning he probably would have been available for only one inning at best for the All-Star Game.
In his second year with the Giants, Lincecum is 11-2 with a 2.57 ERA through 20 appearances. He leads the Major Leagues with 135 strikeouts.
Samantha Newman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.