NEW YORK -- The baseball season is going extra innings.

While the American League playoff picture cleared up Sunday, the National League remained muddled heading into what was supposed to be an off day before the postseason.

AL West champion Houston hosts Detroit, and Baltimore is at home against Kansas City in best-of-three Wild Card Series starting Tuesday. The Astros-Tigers winner faces AL Central champion Cleveland in a Division Series starting Saturday, and the Orioles-Royals winner plays the AL East champion New York Yankees.

The NL is still uncertain because of two rainouts last week caused by Hurricane Helene, with the New York Mets, Arizona and Atlanta vying for the final two wild-card spots in the 12-team playoffs. The Mets traveled back to Atlanta on Sunday and will play a makeup doubleheader against the rival Braves on Monday.

Arizona finished 89-73 and the Mets and Braves are both 88-72. If either team sweeps the doubleheader, the Diamondbacks reach the playoffs. But if the twinbill is split, the Mets and Braves advance and Arizona is out because the Diamondbacks lost their season series to both New York and Atlanta.

Arizona can only be the No. 6 seed if it reaches the postseason and would play a Division Series at NL Central champion Milwaukee.

If the Braves win either game of the doubleheader, they would play a Division Series at San Diego.

If the Mets sweep the doubleheader, they become the No. 5 seed and play at San Diego. If they split and are the No. 6 seed, they go right back to Milwaukee to face the Brewers.

New York beat Milwaukee 5-0 on Sunday to finish 1-5 against the Brewers this season.

Mets right-hander Tylor Megill (4-5) and Atlanta rookie Spencer Schwellenbach (8-7) were scheduled to start the doubleheader opener.

Right-hander Luis Severino (11-7) and Braves ace Chris Sale (18-3) were lined up for the second game, but a team winning the opener was likely to save that starting pitcher for Game 1 of a Division Series on Tuesday.