SAN DIEGO -- The Padres opened their season with a winning homestand, but forgive them if they finished the first week of the season in lower spirits than their 4-3 record would indicate.

Most notably, of course, San Diego lost superstar shortstop Fernando Tatis Jr. to a left shoulder injury on Monday night, and there's not a timetable for his return. The Padres' other early season concerns pale in comparison to the status of, arguably, their most important player.

• Box score

But those other concerns certainly exist -- and they were on full display Wednesday afternoon at Petco Park. The Padres’ defensive struggles continued, and their offense remained cold in a 3-2, 10-inning loss to the Giants in the series finale.

Seven games into the season, here’s the Padres’ Week 1 report card:

Offense: C
The bats started hot enough. The Padres scored 19 runs in their first three games en route to the franchise’s first 3-0 start since 1984. But their offense has cooled significantly since then -- and Tatis’ injury only heightens those concerns.

The Padres built themselves a deep enough bench where they have several candidates to replace Tatis at shortstop. But, to be clear, there’s no “replacing Tatis.” He’s one of the most dynamic offensive weapons in the sport and the spark atop the lineup.

Tatis aside, Manny Machado and Tommy Pham are off to slow starts. Ha-Seong Kim, Tatis’ primary replacement at shortstop, has hit the ball hard, but he has only three hits in 15 at-bats. The Padres have scored just eight runs across their past four games.

Of course, it would be foolish to make too much of such a small sample. Last August, a trip to Texas was exactly what the Padres needed to cure their offensive struggles. This weekend, they’re headed back to Arlington, hopeful for more of the same.

Defense: F
There’s no getting around it, the Padres’ defense has been atrocious through seven games. Their eight errors are the most in the Majors -- and their shoddy glovework came back to bite them again on Wednesday. San Diego committed two errors -- and that doesn’t include two other misplays from center fielder Jorge Mateo and pitcher Tim Hill, which led to all three of the Giants’ runs.

“We’ve got a chance to be a really good defensive team,” said Padres manager Jayce Tingler. “Unfortunately, we didn’t see it on this homestand. There’s some things that we can clean up.”

The Padres should get a huge boost on Friday when Trent Grisham -- the National League’s reigning Gold Glove Award winner in center field -- is expected to be activated from the injured list after missing a week with a right hamstring strain.

San Diego was one of the best defensive teams in baseball last season, and Tingler was quick to note that his defenders have extensive track records of success. We’ll learn soon enough whether the early woes are representative of a small-sample blip or something larger.

“It would be concerning if we don’t clean it up,” Tingler said. “This can’t be a trend. We’ll get it fixed.”

Rotation: B+
So far, the Padres revamped rotation is living up to the hype. Yu Darvish and Blake Snell -- aces acquired via trade on the same December day -- were both sharp against the Giants this week, though Snell fell victim to some shoddy defense on Wednesday. Right-hander Joe Musgrove was the best of the bunch, posting six scoreless innings against Arizona on Saturday.

Through seven games this season, the San Diego rotation owns a 2.88 ERA. If there’s one gripe, it’s that the Padres starters haven’t pitched particularly deep into games. But that’s partly by design this early in the season. Darvish and Musgrove, in particular, cruised through six innings when they were removed on fewer than 90 pitches.

In the meantime, reports on Dinelson Lamet at the alternate training site have been positive, and an early May return seems possible. As Snell was quick to point out Wednesday, the Padres also have Mike Clevinger eyeing a 2022 return following Tommy John surgery.

“I keep looking at Clev walking around all the time like, once he gets back it’s going to be scary,” Snell said. “I keep looking at Lamet walking around, like, oh my God, we have some arms here. … With Darvish, [Adrian] Morejon, [Chris] Paddack, Musgrove -- we’ve got some depth in this starting rotation.”

Bullpen: A
A question mark entering the season, the Padres’ relief corps was spectacular during the first homestand, posting a 0.91 ERA that qualifies as the best mark in baseball.

San Diego entered the year with four candidates for the closer role -- Mark Melancon, Drew Pomeranz, Keone Kela and Emilio Pagán. The team never publicly announced a closer. But with saves in each of his first three appearances, it’s clear Melancon won that role. 

Still, you’d probably feel safe with any of those four getting the ball right now. They’ve combined to pitch 13 2/3 innings without allowing a run, while posting a 0.37 WHIP.

Beyond that group, the Padres have gotten standout performances from Taylor Williams, Ryan Weathers and Nabil Crismatt -- the last three relievers to make the team this spring. With Pierce Johnson and Austin Adams nearing a return from the IL, the Padres could have some difficult decisions to make for the last few bullpen spots. That’s the way they like it.