San Francisco @ Arizona Game Overview

The head-to-head between NL West rivals began on a low-scoring note when the Diamondbacks recorded single runs in the seventh and eighth innings to prevail 4-2 in what had begun as a stellar pitchers' duel between San Francisco's Logan Webb and Arizona's Ryne Nelson.

Gallen (5-9, 5.75 ERA) has gotten a decision in 14 of his 17 starts, including a loss his last time out in a 7-3 road defeat against the Chicago White Sox in which he allowed five runs in 5 1/3 innings.

The loss was his ninth of the season -- three more than he had all of last year when he went 14-6 in 28 starts.

A 10th loss Tuesday not only would see the right-hander join Antonio Senzatela of the Colorado Rockies and Mitch Keller of the Pittsburgh Pirates as baseball's lone double-figure losers so far this season, but also would equal his career high, set in his 4-10 campaign in 2021.

The 2023 All-Star as a 17-game winner -- he also finished third in the NL Cy Young Award voting that season -- went 2-2 in June, but did so with a 6.23 ERA. He has gone winless in his past four starts at home, where he has been particularly ineffective this season, going 1-5 with a 6.29 ERA.

Diamondbacks manager Torey Lovullo said he believes the numbers are misleading.

"There's one pitch per inning that hurts him," the skipper said. "He's going to figure this out. Zac's too good of a pitcher. He's too smart of a pitcher and too hard-working of a player to just let this go."

Gallen did not face the Giants when the clubs met in May in San Francisco, leaving him 6-5 with a 3.94 ERA in 16 lifetime starts against them. Arizona took two of three in that series.

The 29-year-old will see a San Francisco lineup that has gotten into a big-time rut on a 10-game trip that started by losing two of three to the Chicago White Sox, the worst team in the American League. The Giants have scored just seven runs in the first four games of the road swing.

Giants manager Bob Melvin was ejected late in Monday's win, later admitting he was as angry about his club's lack of runs and home plate umpire Quinn Wolcott's wide strike zone.

"We're in this position because we're not scoring enough runs and doing enough offensively," he said. "So it gets frustrating."

Gallen is scheduled to duel another struggling righty, Hayden Birdsong (3-2, 4.13), who is winless in his past four starts, seeing his ERA climb from 2.37 to 4.13. He has been particularly ineffective in his past three outings, during which he has allowed 14 earned runs in 14 1/3 innings.

He has started the past seven games after 11 relief appearances. He threw three innings in relief against Arizona in an 8-7 loss on May 14, allowing three runs, including home runs to Ketel Marte and Eugenio Suarez.

The 23-year-old has faced the Diamondbacks three times in his career, twice as a starter, going 1-1 with a 5.73 ERA.

- Field Level Media