Charlie Morton gave up a three-run homer to Michael Massey in the first inning and the Atlanta Braves squandered a chance to clinch a postseason berth, losing to the playoff-bound Kansas City Royals 4-2 in what was supposed to be the final day of the regular season.

The Braves and Mets are both 88-72, and the other team in the mix, the NL West's Arizona Diamondbacks, beat the playoff-bound San Diego Padres 11-2 on Sunday to finish the regular season 89-73. The Diamondbacks winning also kept the Mets — who won 5-0 against the Milwaukee Brewers, the NL Central champions — from clinching.

Atlanta and the Mets are both 88-72, and Arizona finished 89-73. If either team sweeps today, the Diamondbacks reach the playoffs. But if the doubleheader is split, the Mets and Braves advance and Arizona is out because the Braves and Mets hold the tiebreaker edge against the Diamondbacks.