Dodgers taxed bullpen gives up first homer in 4-2 loss to Diamondbacks

The mounds near the left-field pavilion stood empty as the eighth inning began on Monday evening. The inactivity symbolized both a dearth of alternative options and the temporary trust extended by Dodgers manager Dave Roberts to the most combustible reliever in his bullpen. Chris Hatcher trotted out of the dugout for his second inning of work.

Through the first three weeks of the season, Dodgers relievers faced 181 batters. All 181 stayed within the ballpark. At 9:40 p.m. on Monday, the Dodgers operated the only bullpen in baseball that had yet to yield a home run. A minute later, in the climactic moment of a 4-2 defeat by Arizona, the team lost that distinction, and a game along with it. On the first pitch of the eighth, Diamondbacks third baseman Jake Lamb cranked a waist-high, cut fastball from Hatcher into the right-field bleachers.

“I didn’t think he got it that good,” Hatcher said. “And judging by his reaction, I don’t think he did either. But the ball left the yard.”

The homer stemmed not only from a misplaced pitch, but also from the receipt of the previous two days, when the Dodgers’ starting pitchers combined to log seven innings. Brandon McCarthy struck out eight Diamondbacks, but departed after giving up two runs in five innings. He had thrown only 86 pitches. The outing forced Roberts to lean upon his relievers. Roberts learned to thrive amid this type of tumult in 2016. Monday’s game offered a reminder of the challenges inherent when managing a pitching staff that is long on depth but short on longevity.

“That’s the challenge, every single night, it seems like,” Roberts said.

The performance by Hatcher was not the only voucher accrued over the weekend. In the ninth, appearing for the third day in a row, Luis Avilan gave up an RBI triple to outfielder David Peralta. The long weekend left Roberts with only Hatcher, Grant Dayton and Kenley Jansen as candidates to pitch full innings on Monday.

In defeat, the Dodgers (7-7) botched a chance to win a four-game series with Arizona. After dropping the first two games at Dodger Stadium, the Diamondbacks salvaged a split. The Dodgers remained inefficient at situational hitting. As a group, they struck out 15 times, went hitless in six at-bats with runners in scoring position and stranded seven runners.

A sequence in the bottom of the eighth, after Lamb’s home run fell, epitomized an evening’s worth of frustration. Justin Turner ripped a leadoff double off Diamondbacks reliever J.J. Hoover. The next three batters — Yasiel Puig, Yasmani Grandal and Enrique Hernandez — saw four pitches and popped up three times.

And so the team lost, yet again, when opposing a left-handed starting pitcher. Five of its seven losses have come in this fashion.

The team’s first hit came from a new arrival. The Dodgers called up Rob Segedin from triple-A Oklahoma City after putting Rich Hill back on the disabled list because of a blister. Segedin started in Adrian Gonzalez’s place at first base, and stroked a second-inning single off Robbie Ray.

After Segedin’s hit, Scott Van Slyke walked. The Diamondbacks bungled a bunt by McCarthy when second baseman Daniel Descalso dropped the throw. The error loaded the bases for second baseman Logan Forsythe. Back in the lineup after missing a day to rest his hamstring, he skimmed a line drive into center field, which allowed Segedin just enough time to tag up for the first run of the game.

McCarthy had logged six innings in each of his first two starts. After burning up the bullpen on Saturday and Sunday, the Dodgers required length on Monday. Alex Wood threw 31/3 innings on Saturday and was slated to start on Friday. Ross Stripling collected five outs on Sunday.

The offense handed McCarthy a second run in the bottom of the fourth. Ray challenged Hernandez with a fastball on the inner half of the plate. Hernandez lifted a homer that nestled just inside the left-field pole and just beyond the fence.

At that point, there was little reason for worry. McCarthy could spot his curveball for strikes, and flooded the zone with fastballs and cutters. He fanned six batters in the first four innings. “It was nice to be able to shift gears and get strikeouts back on my side,” McCarthy said.

The lead evaporated in the fifth. After a walk by shortstop Chris Owings, Ray’s single appeared innocuous, a two-out groundball knock on a two-seam fastball that leaked over the plate. The hit became more painful when outfielder A.J. Pollock poked a cutter into center for an RBI single. The next batter, Peralta, tied the score by shooting another cutter up the middle.

“There were some executed pitches, but the balls were going where we didn’t have players,” McCarthy said.

McCarthy recovered to strike out four-time All-Star Paul Goldschmidt to strand runners at the corners. Roberts felt McCarthy could provide one more inning. He opted for his bullpen instead. After a scoreless inning from Grant Dayton in the sixth, Hatcher took over the game. The loss hung on his shoulders.

“Usually your outing is going to be dictated by one pitch,” Hatcher said. “Tonight, that was it.”

andy.mccullough@latimes.com

Twitter: @McCulloughTimes