Column: Dodgers have struggled with Arizona, but schedule should keep them in race to the finish

Still trailing a couple of mediocre teams in their division, the Dodgers are about to unleash a secret weapon.

It’s not an extra arm in the bullpen. They’re counting on Kenley Jansen to straighten himself out.

It’s not a hitter who can drive in runs. Anyone who slips on a Dodgers uniform these days is taken over by the spirit of Logan Forsythe whenever runners are on base.

And it’s not another starting pitcher. The rotation isn’t a problem.

The Dodgers have something more reliable at their disposal: the schedule.

So, yeah, the season has come to this. But, hey, it’s something.

As the Dodgers demonstrated again in a 3-1 defeat Thursday night at Dodger Stadium, they can’t be counted on to beat the first-place Arizona Diamondbacks. They have dropped nine of 13 against the hosts of the most famous pool party ever staged in the Phoenix metropolitan area. They trail the Diamondbacks by two games in the National League West.

The Dodgers thought they would have some momentum on their side entering this critical four-game series, as they’d won their previous five games.

The streak was exposed as a mirage. Diamondbacks starter Robbie Ray is in the latter stages of a trying season, but the Dodgers practically made him look like Sandy Koufax, scoring their only run against him on a solo home run by Manny Machado in the sixth inning.

The five-game winning streak nonetheless provided useful information. Victories over the San Diego Padres and Texas Rangers proved the Dodgers can triumph against awful opposition. And over those five games, the Dodgers reduced their deficit against the Diamondbacks from 41/2 games to one. These aren’t the 1927 New York Yankees they’re pursuing.

The Diamondbacks’ next series is against the last-place Padres. So is their last.

But there are no soft touches in between.

Four games against the National League East-leading Atlanta Braves. Seven against the second-place Colorado Rockies. Three against the Dodgers. And a brutal stretch from Sept. 14-19 that includes three games at Houston and three at home against the NL Central-topping Chicago Cubs.

Now look at some of the patsies remaining on the Dodgers schedule.

Once the Diamondbacks leave town, Dave Roberts’ team will have three home games against the dreadful New York Mets. They have three at Cincinnati. They have three home games against the tanking Padres. And they close the season against the delightfully pitiful San Francisco Giants.

It’s true the Rockies are still in the race and that their schedule falls somewhere between the Diamondbacks’ and Dodgers’ in difficulty. But the Rockies stink. They shouldn’t be around much longer.

Of course, trudging into the playoffs like this won’t address any of the Dodgers’ long-standing problems.

Five months into the season, their shortcomings can no longer be viewed as blips. This is who they are.

With every batter taking the first pitch from Ray through the first five innings, the Dodgers successfully ran up the opposing starter’s pitch count. They just couldn’t do anything with it.

Justin Turner and Machado drew consecutive walks in the first inning, only for Matt Kemp and Enrique Hernandez to end the threat by striking out.

They had Ray similarly cornered in the fourth inning. This time, Chris Taylor struck out and Yasiel Puig grounded out.

And then there was a real backbreaker in the eighth inning, when the Dodgers had runners on the corners with one out against reliever Yoshihisa Hirano. Kemp grounded into an inning-ending double play.

As for the troubled bullpen, it didn’t factor in this defeat. After David Peralta blasted a three-run home run in the fifth inning against starter Rich Hill, the Dodgers trailed the remainder of the game.

Roberts said before the game that Jansen would remain the Dodgers closer, even though he has given up four home runs and posted a 15.75 earned-run average in four appearances since his stint on the disabled list because of a heart problem.

“I still think that he’s earned that,” Roberts said.

Roberts acknowledged that it’s hard for a pitcher, especially a key reliever, to work on mechanics between games. Throwing in games limits how much he can throw beforehand.

Jansen was therefore limited to watching videos of himself and making somewhere between 10 and 15 throws on the eve of the opener against the Diamondbacks.

“There’s no wavering in trust,” Roberts said. “We’ll bet on Kenley.”

This didn’t sound particularly convincing. Then again, it didn’t have to. If Jansen can’t shut down the Diamondbacks, the Astros and Cubs can.

dylan.hernandez@latimes.com

Follow Dylan Hernandez on Twitter @dylanohernandez