The Royals waited 29 long years to get back to the postseason. And their stay could last all of three hours.

Welcome to the cruel new world of Major League Baseball’s playoffs.

“I don’t want to play one game,” Tigers general manager Dave Dombrowski was saying Sunday.

And, the Tigers don’t have to, because they held off the Royals by a single game in the American League Central. That means if Kansas City wants to play in a Division Series, it’ll have to beat Oakland in a do-or-die game Tuesday night at Kauffman Stadium. First pitch is 8:07; it’ll air on TBS.

The game will feature ace against ace, James Shields facing perhaps his final start with the Royals, and Jon Lester doing the same with the A’s.

This game has all the makings of a low-scoring affair, not just because of the starting pitchers, but because the offenses are abysmal — Oakland’s slumped mightily ever since it traded away Yoenis Cespedes to acquire Lester, and Kansas City’s been pretty rotten all season, sans a few hot stretches.

So you can expect small ball early, particularly from Royals manager Ned Yost, who never saw a bunting opportunity he could pass up.

A’s player to watch: Adam Dunn — Just acquired from the White Sox, he’s in the playoffs for the first time. One swing could decide this one. It might just be his.

Royals player to watch: Mike Moustakas — The Royals are sticking with the slumping third baseman, even against a tough left-handed pitcher in Lester.

A’s edge: Lester — He’s as playoff-tested as they come, pitching for a team that’s no stranger to do-or-die games.

Royals edge: The bullpen — It was stacked to begin with, and now might have Yordano Ventura available, too.

At stake: Winner plays the Angels in the ALDS.

Prediction: Royals, 2-1 — They’re playing well, and the A’s are in a funk that’s been around for too long to be a fluke.