PHOENIX — For the first time since Buster Posey’s playing days, the San Francisco Giants have fallen 10 games below .500.

The Giants unceremoniously concluded their three-city trip by being swept by the Arizona Diamondbacks on Wednesday afternoon with a 6-3 loss. With a 20-30 record, the team is 10 games below .500 for the first time since July 1, 2019.

San Francisco finishes its 10-game circuit away from the Bay with a disappointing 4-6 record. The Giants split their four-game series against the Los Angeles Dodgers, winning the first two games but dropping the latter two. They responded by taking two of three against the Athletics, needing just one win against the Diamondbacks to at least finish their road trip with a .500 record.

Instead, the Giants leave the desert empty-handed. On Monday, they were blown out. On Tuesday, they blew a two-run lead as Ketel Marte hit a walk-off homer. And on Wednesday, the Diamondbacks finished the dusting.

Right-hander Tyler Mahle turned in another subpar start, allowing six earned runs (and one homer) over five innings.

Through 10 starts, Mahle owns a 6.10 ERA, the worst mark among any qualified pitcher in the majors. With Trevor McDonald pitching well (2.37 ERA) and Logan Webb nearing his return from right knee bursitis, the Giants will soon have to decide whether to keep Mahle in their rotation.

Top prospect Bryce Eldridge, who sat on Tuesday after collecting two hits on Monday, was one of the few bright spots in Wednesday’s loss. Eldridge smashed an RBI double in the top of the second with an exit velocity of 113.4 mph, the hardest-hit ball by a Giant this season.

Casey Schmitt, making his second career start in left field, hit his team-leading ninth home run of the season, a solo shot in the top of the first.

San Francisco and Arizona each put up three runs apiece through the first four innings. The Giants manufactured their offense on Schmitt’s solo homer (first inning), Eldridge’s RBI double (second inning) and Drew Gilbert’s RBI single.

As for the Diamondbacks, their first three runs all stemmed from Ketel Marte, who hit a walk-off homer on Tuesday. Marte hit a leadoff double in the first and scored on a sacrifice fly by Geraldo Perdomo, then cleared the fences for the second time in the last 24 hours with a two-run homer in the third.

Worth noting

Right fielder Jung Hoo Lee sat out a second straight game after leaving Monday’s game with back spasms. With an off day on Thursday, the Giants wanted to get Lee three consecutive off days ahead of their series against the Chicago White Sox.

Up next

Following an off day on Thursday, the Giants will begin a six-game homestand on Friday, beginning with three games against the Chicago White Sox. McDonald, Adrian Houser (a former White Sox) and Robbie Ray are slated to start against Chicago this series, in that order.