Here’s how the Dodgers wound up fighting for their lives in the NL West

Dave Roberts recalled the play a couple of times late Wednesday night. If Yasiel Puig hadn’t clubbed his 100-mph line drive right to the shortstop, the game, he reiterated, would’ve gone differently. The bases were loaded with one out in the third inning. If the ball found a hole, two runs would’ve scored, giving the Dodgers the lead. From there, who knows?

“If it goes a different way, it’s a different ballgame,” Roberts said. “But that’s baseball.”

The Dodgers left the bases loaded. They went on to lose to the Arizona Diamondbacks, a club that had played its way out of contention before the Dodgers arrived, and dropped to second place behind the Colorado Rockies in the National League West.

It was not supposed to go like this. Roberts was not supposed to agonize over a play in Game 159. The Dodgers (88-71) were the consensus NL West favorites after going to Game 7 of the World Series. They were supposed to have their sixth straight division title sewn up by now. An uncomfortable playoff race wasn’t on the radar.

“When it’s all said and done,” Roberts said in late April, “the Dodgers will be at the top of the division.”

Roberts made that declaration as his club reeled. The Dodgers started 16-26, but the organization was confident its talent would prevail in the NL West. There’s still a chance it will. There’s also a chance it won’t. It all depends on what transpires at AT&T Park and Coors Field over the next three days. The Dodgers will open Friday’s series against the San Francisco Giants a game behind the Rockies. Colorado will finish the season hosting the Washington Nationals for three games.

“It’s kind of the classic control what you can control,” Dodgers right-hander Ross Stripling said. “Go try to win three games in San Fran. It’ll probably take three wins to take the division, I would guess, based on how the Rockies are playing at home right now. But we can’t do anything to affect them. They’re going to do their thing.”

It is not division-or-die for the Dodgers. The second wild-card spot serves as a safety net. They lead the St. Louis Cardinals by a game for that playoff berth. The Cardinals finish their season with a three-game set against the Chicago Cubs, who are also scrapping for playoff positioning.

Combing through the possible scenarios for Los Angeles is mind-numbing. They range from clinching the National League West this weekend, to playing three games in three cities in three days before Game 1 of the National League Division Series on Thursday, to having their season end Sunday without a postseason berth for the first time since 2012.

“Just prepare to win a game on Friday,” Dodgers third baseman Justin Turner said. “There’s nothing else you can do.”

The Dodgers will deploy their three best starting pitchers in San Francisco. Hyun-Jin Ryu, who has a 1.93 ERA in eight starts since coming off the disabled list last month, will take the ball opposite Madison Bumgarner in Friday’s opener. It’ll be Clayton Kershaw against rookie right-hander Dereck Rodriguez on Saturday. Walker Buehler and left-hander Andrew Suarez are scheduled for Sunday’s finale. The Dodgers are 7-9 against the fourth-place Giants, another example of their puzzling inability to beat bad teams at the expected rate. A sweep might be required for a chance to reclaim the division title.

“As far as going to the postseason, it takes us,” Roberts said. “We control our own fate. We’ve got to win baseball games. Those guys have got Bumgarner going and they’re going to bring their best. Again, for us, there’s a little back against the wall, but I know we’re going to come out and play on Friday. We’ll be ready to go.”

If the Dodgers and Rockies finish tied, they will play for the division crown Monday at Dodger Stadium because the Dodgers won the season series. Rich Hill would start that game for Los Angeles. The teams would have expanded rosters at their disposals since it would qualify as a regular-season game.

On Thursday, FanGraphs calculated there was a 29.2% chance the clubs would finish even after 162 games. A week ago, the possibility was more far-fetched. The Dodgers had just swept the Rockies in Los Angeles to build a 2½-game division lead, their largest this season. Since then, they’ve gone 3-3 against the last-place San Diego Padres and Diamondbacks, while the Rockies have won seven straight.

The Dodgers haven’t enjoyed any margin for error. They weren’t supposed to need any. Now they must battle to the end with an eye on the out-of-town scoreboard, every moment potentially carrying season-changing implications.

“However it plays out is the way it plays out,” Roberts said. “But I know we’re a very dangerous team. I know we believe in ourselves. It’s now how we scripted it, but that’s why you got to go out and play. Now our focus has to turn to the Giants.”

jorge.castillo@latimes.com

Twitter: @jorgecastillo