Diamondbacks get three runs off Jansen, two in 15th for double comeback win

At first, the drama played out beyond the field. The display for the radar gun at Chase Field resides on a screen in the right-field seats, above an advertisement for a bar and below the plaques commemorating the two retired numbers in Arizona Diamondbacks history. On Monday evening, as the Dodgers protected a three-run lead, the pixelated digits carried more weight than usual.

The gun tracked the speed of Kenley Jansen’s cut fastball: 90 mph . . . 88 mph . . . 89 . . . 92 . . . 91. A pitcher of Jansen’s pedigree rarely receives such scrutiny. But those were the consequences after his first outing of the season, in which his velocity averaged 89.6 mph and he shrugged off questions in search of explanation.

Jansen received two days off after his 2018 debut. He spent them cleaning up his delivery to regenerate the velocity he once produced, a steady stream of 93-mph cutters. In his second outing of the season, Jansen managed to improve his velocity. Except as the focus on the radar gun intensified, Jansen immolated on the mound in a game the Dodgers eventually lost, 8-7, in 15 innings.

The ending added to the frustration. A two-out single by Chase Utley brought home Cody Bellinger in the 15th. Asked to protect the lead was Wilmer Font, who was pitching his fifth inning. He gave up a game-tying double to shortstop Nick Ahmed and a walkoff single to Jeff Mathis.

The defeat stung. The performance by Jansen was more troubling.

“Just didn’t execute,” manager Dave Roberts said.

After issuing consecutive walks with two outs, Jansen served up a 90.5-mph cutter to outfielder Chris Owings. The location was “in his nitro zone,” Roberts said. The ball landed deep in the left-field seats, a three-run blast that tied the score 6-6 and ruined an otherwise sterling outing from the Dodgers bullpen, which pitched 4 1/3 scoreless innings after a brief outing by Hyun-Jin Ryu. Jansen could not protect the advantage.

Jansen hung his head as he walked off the field. He looked off-kilter throughout the outing. The velocity looked better. His delivery did not. His command wavered as he heaved himself toward the plate. Inside the dugout, he rubbed his right shoulder as the Dodgers played past midnight, a five-hour, 45-minute affair that was the longest game in Chase Field history.

Perhaps Jansen requires more tinkering with his mechanics. Perhaps he is still plagued by the hamstring issues that slowed his spring training. Perhaps he needed a heavier workload this spring, when the Dodgers used him sparingly. Or perhaps this is an inevitable outcome for a 30-year-old pitcher who has averaged 66 regular-season appearances since 2012 and has pitched into October every season since 2013.

Both Jansen and Roberts insisted the pitcher was healthy. Jansen admitted he was “fighting with some stuff” mechanically. But he said his body was not bothering him.

“I’m fine,” Jansen said.

Added Roberts, “From everything I understand, he is 100% healthy.”

The explanation will appear in time. Until then, the Dodgers know this: Jansen has pitched twice this season. He lost the first game. In his second, he matched his total of blown saves from 2017. He has given up two homers in two games; he gave up five in 2018. He is the foundation of the team’s bullpen, and he has been the least reliable pitcher of the group in this minuscule sample size.

“It sucks,” Jansen said. “A slow start. But nobody is going to feel sorry for me.”

To start a night when he reached base five times, Yasmani Grandal launched a first-inning blast to cap a three-run blitz of Diamondbacks starter Taijuan Walker. Struggling to throw strikes, Ryu coughed up the lead over 3 2/3 innings. A solo shot by Logan Forsythe gave the Dodgers the lead in the sixth. Grandal cracked a two-out double in the seventh and scored on a single by Cody Bellinger for insurance. An inning later, Joc Pederson contributed a two-out run-scoring single.

The Dodgers faced Walker for the first time since pummeling him in October. Walker started Game 1 of a National League division series. He lasted precisely one inning, giving up four runs before exiting the premises.

Walker did better Monday. He cleared a low bar. He still gave up three runs.

The first man up for the Dodgers was an unlikely choice. Roberts selected Pederson as his leadoff hitter. With Chris Taylor getting a day off, Roberts opted for Pederson to replace him, despite no hits in his first six at-bats. The cold streak ended against Walker.

Pederson stung a full-count fastball for a double. Two pitches later, Corey Seager pulled a fastball into right field for a run-scoring single. Seager was still at first when Grandal came to the plate. Walker fell behind in the count and fed Grandal a two-seam fastball down the middle. Grandal launched the baseball into the pool area beyond the right-center fence.

Walker weathered the early flurries. The lead slipped from Ryu’s grasp inning by inning, as his command of the strike zone wavered.

Ryu gave a run back in the first inning. After two speedy outs, Arizona first baseman Paul Goldschmidt blasted a double off the center-field wall. A trio of changeups did not fool outfielder A.J. Pollock. Pollock deposited the third into left for a run-scoring double.

The Diamondbacks tested the Dodgers outfield defense in the third. In the first at-bat of the inning, David Peralta lifted a ball into the left-field corner. Matt Kemp took a twisting route toward it. He banged his left leg into the fence as he skidded to a stop. Pederson trotted over to check in on his teammate.

Pederson returned to center field. The next ball caught him flat-footed. A drive from second baseman Ketel Marte sailed over Pederson’s head. Marte landed at third base with a one-out triple.

Ryu slipped deeper into the muck. He walked Goldschmidt and Owings. With two outs and the bases loaded, Ryu faced third baseman Jake Lamb. In 2017, Lamb hit .144 against left-handed pitchers like Ryu. This time, he didn’t even have to swing. Ryu walked Lamb on four pitches to drive in a second Diamondbacks run.

Ryu was still disconnected from the strike zone when the fourth began. He issued his fifth walk to open the frame. Bailed out when Walker grounded into a double play, Ryu could not escape. He gave up a single to Peralta. Marte smoked a hanging curveball for a run-scoring triple. The hit tied the score and ended Ryu’s evening.

Walker gave up eight hits and two walks in five innings. But the Dodgers could not score against him after the first. The offense pounced on the arrival of right-handed reliever Yoshihisa Hirano. Forsythe unloaded on a 1-0 fastball in the sixth and homered to center to reclaim the lead for the Dodgers.

The Dodgers piled on runs in the seventh and the eighth. The bullpen held the line. They passed the baton to Jansen, who had not pitched since Saturday. His velocity started to increase as he retired the first two batters. Then came Goldschmidt.

Goldschmidt worked the count to 2-2. Jansen missed outside with a pair of cutters. Up came Pollock. Again Jansen got ahead in the count. And again he missed outside, the cutters straying from the zone for a free pass. Jansen walked his first batter in 2017 on June 25.

“I tried to just go out there and attack,” Jansen said. “It didn’t go my way.”

Owings did not take a passive approach. Jansen spun a cutter at the level of Owings’ belt. Owings crushed it.

The game would not end for another two hours and seven minutes. Font dragged his team past midnight before succumbing in the 15th. The team may need to make a roster move to compensate for the depleted pitching staff. Jansen felt responsible for the mess.

“It sucks,” Jansen said. “We lost.”

andy.mccullough@latimes.com

Twitter: @McCulloughTimes