"I knew he was going to be leading off before we left Peoria," Shields said. "I love Nori. ... I loved playing with him. He's always good to see. I guess it's only fitting to face a former teammate your first at-bat."
Shields, making his first appearance in a Padres uniform, allowed one hit in his only inning, an 11-pitch first inning that saw him throw six strikes.
It was hardly enough for him to work up a sweat, so much so that he considered a few extra pitches in the bullpen afterward before ultimately passing.
"He threw the ball well. He was efficient, he was good," manager Bud Black said. "He's 33, he knows what he's doing out there."
Shields, who last month signed the largest contract in franchise history (four years, $75 million), declared the day a good starting point for him.
"It's a process," Shields said. "More importantly, my body feels good, my arm feels good. It's nice to get a little adrenaline [going]."
Shields got Aoki to ground out to second base, got Joe Panik on a fly ball to right field, allowed a soft single to center field to Angel Pagan and then got Buster Posey on a ground ball to shortstop, a force play as Alexi Amarista tossed the ball to second baseman Cory Spangenberg, who stepped on the bag.
Truth be told, he might have spent more time answering questions from reporters than he did on the mound.
Shields mostly threw fastballs Saturday and will do that, along with his changeup, for his early outings. He will mix in his secondary pitches in his third or fourth outings, he said.
"It's a constant delivery work during Spring Training, trying to get the timing down," he said. "And it's having [new catcher Derek] Norris down there, getting to know him.
"The main thing right now is to build arm strength."
Shields was asked about the Giants' interest in him this offseason before he settled on the Padres, which he delicately danced around.
Shields did say he's ready to take on the challenge of helping the Padres move upward in the National League West, which includes the World Series champion Giants.
"Three championships in the last five years, they're definitely the team to go after, for sure. I like the challenge," Shields said.