Curt Schilling gave up a first-pitch, ninth-inning, walk-off gopher ball to Vladimir Guerrero yesterday to break a 1-1 tie, thereby failing his in his first attempt at 19 wins. But in the larger picture, Schilling whose Diamondbacks had 55 games remaining before the game, lost even the remotest possibility of getting 30 wins given the team's remaining schedule. Prior to the game, Schilling would have needed the stars to align to get to 30: he had to win all of his remaining starts (12 based on his pitching every five days). Now the only possibility is for him to win his next ten scheduled starts and then get a break to pitch one day early on the last day of the season at home against the Rockies (9/29). Would the D-Backs risk such a thing with a playoff series starting two days later, a series for which Schilling could be well rested to pitcher the opener? I would have to think not.
There is one other possibility, or maybe two. The first is a playoff game for the division or the wild card. If the D-Backs are tied with another team at the end of the regular season, the would play a one-game playoff, it would be Schillings turn in the order, and the statistics would count in the regular season. This is rather a rare occurrence (especially given Arizona is 5 games up in the NL West) but the addition of the wild-card team increases the possibility.
The other possibility is even more remote. Say the D-Backs get rained out between now and the end of the season (not on a Schilling start day), and the game cannot be made up during the season. If the game affects the pennant race, they would have to play the game after the season. This is remote given that they play half their games in the arid Ariozona air. But again Schilling would be the pitcher and the results would be counted in the regular season stats.