Manager Mike Matheny, who will lead the National League, said the right-hander told him before Sunday's game against Milwaukee that he felt good and could go at the All-Star Game at Target Field.
Wainwright is 12-4 with a 1.83 ERA. Tuesday would be his scheduled day to throw in between starts. Matheny said Wainwright hasn't done much lobbying to pitch.
Matheny is making his first appearance as an All-Star manager. He said he expects his players to compete like their "postseason is on the line."
The Cardinals were trying to finish a three-game sweep Sunday in Milwaukee.