SAN DIEGO -- The Giants are still working to determine when left-hander Blake Snell will make his season debut, but Sunday afternoon showed why they could use the reigning National League Cy Young winner in their starting rotation sooner rather than later.

With Snell unavailable for the first turn through the rotation, the Giants called up right-hander Daulton Jefferies to make a spot start in their series finale against the Padres, but the move didn’t end up panning out as expected.

Making his first big league start since May 18, 2022, Jefferies was rocked for nine runs (five earned) on five hits over two innings, resulting in a 13-4 blowout loss on Easter Sunday at Petco Park.

The Giants endured a nightmarish first inning that featured an error by shortstop Tyler Fitzgerald on the first play of the game, a run-scoring passed ball by catcher Patrick Bailey and a three-run blast by Luis Campusano that capped a quick five spot for San Diego.

The Padres continued to pile on against Jefferies in his second inning, stretching their lead to 9-0 behind an RBI double from Jake Cronenworth and a three-run homer from Ha-Seong Kim. It certainly wasn’t the start Jefferies envisioned after completing his long road back from thoracic outlet surgery and Tommy John surgery, which forced him to miss the entire 2023 campaign.

“I’m happy to get back on the mound,” Jefferies said. “It was a long road. But at the end of the day, I didn’t really do my job. I could feel good all I want getting back here, but when I got here, I wanted to compete and help the team win. I just didn’t do that today.”

To make matters worse, the Giants also lost first baseman Wilmer Flores, who suffered a right shoulder contusion after flipping over the Padres’ dugout railing while attempting to catch a foul ball off the bat of Fernando Tatis Jr. in the bottom of the first. Flores didn’t require any tests after the game, but he said he was sore and would be reevaluated on Monday.

Right-hander Kai-Wai Teng took over for Jefferies in the bottom of the third, giving up three runs on four hits over three innings in his Major League debut.

Teng, the 17th Taiwanese-born player in Major League history and the first for the Giants, came away with a unique gift, as he received a glove from his favorite pitcher, Padres ace Yu Darvish, after earning his first callup on Friday.

“That’s the most meaningful moment in my life so far,” Teng said via interpreter Matt Chan.

Also making his pitching debut for the Giants? Fitzgerald, who worked the bottom of the eighth to help save San Francisco’s bullpen ahead of the club’s upcoming three-game series at Dodger Stadium.

Keaton Winn is slated to start Monday’s series opener, but the Giants haven’t announced probables for the rest of the series yet. Snell, who signed a two-year, $62 million deal on March 19, could be an option to pitch Wednesday’s finale after throwing four innings in a Minor League game on Friday. He said he’s feeling good physically, but nothing has been set in stone as far as when he’ll make his first official appearance for the Giants.

"I have ideas, but nothing solid yet,” said Snell, who struck out 11 and allowed three hits while throwing 71 pitches against the Giants' Double-A team. “Next couple of days, we’ll know.

“I feel good. Just get more reps, get better and better, stronger and stronger. When we get out there, that will be the real tell of where I’m at and what I need to work on. I’ll get better from there.”

Snell has dominated the Dodgers in the past, logging a 2.59 ERA over 13 career starts against the Giants’ archrivals, but he’s also been a historically slow starter and ended April with a 5.48 ERA last year.

“We don’t talk about that, but I’m aware of that,” manager Bob Melvin said. “So is he.”

In the meantime, Snell relished his return to San Diego, where he received a warm reception after being shown on the Petco Park scoreboard on Saturday. While he enjoyed his three seasons with the Padres, he said he’s been impressed by what he’s seen from his new club – Sunday’s finale notwithstanding.

“We’re going to be really good,” Snell said before the game. “We’ve got more key pieces coming back. We’re going to be a really, really good team. I’m excited, and we all gel really well already. I really can’t wait.”