The magical weekend for the Atlanta Braves came to a crashing end on Sunday. The Braves started the afternoon with two different ways to clinch a postseason berth: a win or a loss to the Arizona Diamondbacks.

Neither happened.

Because of the Diamondbacks’ win, the Braves had to play Monday no matter what. But with their own loss, the Braves now need to secure at least one win on Monday to continue playing baseball in October.

With their season on the line, the Braves will start right-handed rookie Spencer Schwellenbach in the first game of the doubleheader.

National League Cy Young frontrunner Chris Sale will pitch in Game 2 if necessary.

No matter who wins the first matchup on Monday, Game 2 will be necessary. But if the Braves win with Schwellenbach on the mound, then there is no need for the Braves to try to win Game 2.

Should the Braves lose the first game, Sale will start the second game, which will be a must-win for Atlanta to advance to the postseason.

Both the Braves and Mets must split the doubleheader to clinch an NL wild card spot. If either team wins both games on Monday, the Diamondbacks will secure the final postseason berth.

Braves manager Brian Snitker is doing what he can to save Sale for the postseason. That’s not a strategy I normally support.

Teams can only win the game in front of them. Had the Braves won on Sunday, they would already be in the postseason.

But the way Snitker has set up the team’s rotation since the hurricane ripped through Atlanta has largely worked. Max Fried and Reynaldo López delivered great performances in victories on Friday and Saturday.

Charlie Morton has performed well under pressure in the past, so you can’t blame Snitker too much for the missed opportunity on Sunday.

Snitker could pitch Sale in the first game to reduce the chance of a do-or-die scenario in the second half of the doubleheader. But that would mean that Sale will not pitch at all in the wild card series next week.

If Schwellenbach can lead the Braves to victory in the first game of the doubleheader, Sale will start Game 1 of the wild-card series.

Schwellenbach just defeated the Mets last Tuesday, giving up just 1 earned run on 3 hits and a walk in 7 innings. He hasn’t allowed more than two runs in any of his last three starts.

It will be interesting to see if the confidence Schwellenbach gained from that start will give him an advantage on Monday or if the Mets hitters learned something from that loss.

The Braves winning the first game is Schwellenbach’s top priority. That will save Sale. But winning the first game will keep Snitker from using more bullpen arms in the second. Schwellenbach throwing deep in the first game will have the same impact.

It’s a lot to ask of a rookie, but Schwellenbach has risen to the challenge for most of this season. His start Monday could determine not only whether the Braves make the playoffs, but also how prepared the team’s pitching staff will be to win the opening postseason series.