The Giants avoided a sweep in San Diego with a 7-1 win over the Padres on Sunday afternoon at Petco Park, but they lost another second baseman in the process. 

Tommy La Stella , the Giants’ biggest offseason acquisition, was forced to depart early after suffering a left hamstring strain in the fifth inning and will undergo an MRI exam on Monday.

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After lining an RBI triple off San Diego right-hander Joe Musgrove, La Stella scored on a groundout by Wilmer Flores to extend the Giants’ lead to 6-1, but he pulled up lame as he crossed home plate. La Stella then walked off the field alongside head athletic trainer Dave Groeschner.

“Obviously, he didn’t look good coming off the field,” manager Gabe Kapler said. “Anytime that happens to one of the core pieces of your team, anybody on your team, it’s concerning. For both Tommy and for the Giants, I have concern.”

Evan Longoria entered the game to play third base in the bottom of the fifth inning, with Flores shifting to second to replace La Stella, who also jammed his left thumb while diving for Trent Grisham’s double in the third.

“He plays so hard,” Kapler said. “Tommy shows you that every play is big. He’s diving for anything that he’s close to getting to and runs the bases so hard and prepares so well. That makes it even more disappointing to know that he may be down for a bit.”

La Stella’s injury is another troublesome development for the Giants, who improved to 17-11 despite watching two of their best hitters -- right fielder Mike Yastrzemski (left oblique strain) and second baseman Donovan Solano (right calf strain) -- land on the injured list in recent weeks. Shortstop Brandon Crawford also did not play for the second consecutive game after being drilled on the left calf on Friday, further testing the Giants’ infield depth.

La Stella, 32, entered Sunday batting only .215 with a .589 OPS, but he had enjoyed a productive day against the Padres, going 2-for-3 with two RBIs.

The Giants have been using La Stella as their primary leadoff man against right-handed pitching, so losing the lefty bat for an extended period would be a blow to a lineup that still hasn’t settled into a consistent groove this year. Flores, Mauricio Dubón and Jason Vosler would be candidates to fill it at second base if La Stella winds up on the IL.

“It would be tough losing him,” right-hander Kevin Gausman said. “He just battles. Every AB is a quality AB. He sees so many pitches every at-bat. It would definitely be a blow, but those types of things happen, and the next guy gets to just kind of slot in and do his job.”

Gausman held the Padres to one run -- a home run by Fernando Tatis Jr. -- over six innings to pick up his second win of the season and help the Giants even their season series against the Padres to 3-3. While the Dodgers and Padres have dominated the headlines, the Giants have quietly risen to the top of the National League West over their first 28 games thanks to their outstanding starting rotation, which has logged a Major League-best 2.34 ERA this year.

The Giants showed they have the talent to match the Padres’ firepower on the mound, as Logan Webb , Anthony DeSclafani and Gausman were able to hang with Yu Darvish, Blake Snell and Musgrove over the weekend.

“I think there’s a mutual respect for the talent,” Kapler said. “I certainly think their team is incredibly talented. I think they’re a well-coached team and a well-prepared team, and I think the respect is returned and I appreciate that.”

Gausman had been due to pitch on Friday, but the Giants decided to push his start back to give him extra rest after he experienced right groin tightness following his last start against the Marlins on April 24. 

The 30-year-old veteran appeared unencumbered on Sunday, scattering six hits while walking one and striking out six in the 95-pitch effort. Gausman, who has pitched at least six innings in each of his six starts this year, lowered his ERA to 2.04. Gausman was also busy on the basepaths, reaching on an error by Musgrove in the third and on a single to left field in the fifth. He scored twice.

The Giants also received a jolt from right fielder Mike Tauchman, who crushed his first home run for his new club, a three-run drive off Musgrove to give San Francisco a 4-1 lead in the third inning. Acquired earlier in the week from the Yankees in exchange for left-hander Wandy Peralta and a player to be named later, Tauchman collected his first homer since 2019 in only his 14th plate appearance with the Giants.

“I hadn’t played two games in a row since like August of last year, including Spring Training, so the more pitches you see, the more comfortable you get,” Tauchman said.

While he hasn’t been around the Giants for long, Tauchman said he believes his new squad will have the ability to stick around and continue to exceed expectations in the NL West.

“It is a long season, but I have no doubt that this team is capable of some really great things,” Tauchman said. “There’s a lot of veteran leadership in the room and a lot of talent in the room. The way that our starting pitching has been pitching overall and our ability to grind out at-bats, I think we’re going to win a lot of close ballgames and we’re going to be in a lot of games. When you’re in the game every single night, good things can happen.”