They will wait out the rain as long as it takes the get three games in by end of day Thursday, because the logistics of making up a rainout in Denver later in the season is so difficult. If they still can’t manage to do so, they might make up the game on July 17, the last day of the All-Star break, when the Tigers are on their way to Texas for a series starting the next day, and the Rockies are preparing to start a home series. They’d have to coordinate with the All-Star managers to not play them, at least much, during that game. It would probably be a late afternoon game, like a 4pm start, to maximize TV exposure for Tigers fans.