He learned after the Padres' 2-1 exhibition victory over the Royals on Tuesday night at Petco Park that he made San Diego's Opening Day roster, winning the final bench spot.
Parrino made his big league debut with the Padres last season, but Thursday's game against the Dodgers will be his first Opening Day.
"It's always nice to be able to start the season up here," said Parrino, who hit .182 in 24 games with the Padres last season. "After last year, I think I feel a little bit more comfortable and a little more relaxed. So, hopefully [I'll] be better off this year than last."
Reliever Micah Owings and outfielder Jeremy Hermida also earned spots on the team. The Padres put outfielder Mark Kotsay on the disabled list with a strained right calf. To make room for Hermida on the 40-man roster, the Padres put pitcher Jose De Paula on the restricted list. De Paula is in the Dominican Republic resolving a visa issue, Padres general manager Josh Byrnes said.
First baseman/outfielder Kyle Blanks and reliever Anthony Bass also made the Opening Day roster. The Padres optioned reliever Brad Brach and utility player Everth Cabrera to Triple-A Tucson.
Byrnes called choosing between Parrino and Cabrera for the utility spot, "a very hard decision." Cabrera hit .210 this spring, while Parrino hit .212 and smacked five home runs.
"[They are] two switch-hitters who can play all over," Byrnes said. "Where we are, Parrino probably swung the bat a little bit better. They both deserve a lot of credit. After many meetings, we decided to go with Parrino."
Hermida hit .313 this spring and was the last non-roster invitee in camp. He takes the place of Kotsay, who didn't play Tuesday, as he took another day to rest his strained right calf. He suffered the injury in Saturday's game against the Mariners.
"When a left-handed-hitting outfielder goes down, he certainly stood a good chance," Byrnes said of Hermida. "His bat looked quick. He had a good spring. He swung the bat well. He can play a couple spots in the outfield. He obviously has experience."
A year ago, Hermida started the season in Triple-A. He's hit .257 in 619 big league games.
"Last year was the first Opening Day I had missed in five years," Hermida said. "It definitely gives you more of an appreciation for it and humbles you a little bit. It definitely makes it special to be here knowing you worked hard to get back."
For the final bullpen spot, the Padres picked Owings, who posted a 7.62 ERA this spring, over Brach, who had a 1.69 ERA. Owings can pitch in long relief and has been a starting pitcher in the past, which is something the Padres might need. Starting pitcher Tim Stauffer will miss the first series of the season because of a strained triceps.
Parrino and the other players learned the news after Tuesday night's exhibition. Parrino said he had no idea what the decision was when he was summoned.
"All spring, it was a battle," he said. "You just keep working, and hopefully it pays off in the end. It was nice to find out tonight, and I will be ready for Thursday."
A product of Le Moyne College, a small school in Syracuse, N.Y., Parrino embraces the underdog role.
"When I was younger, my dad said, 'There's always somebody out there working harder,' and I really take that to heart," Parrino said. "I've tried to really work hard to just show them what I have, and they can make the decision from there."
But rather than call and wake his family at 1 a.m., Parrino was planning to wait to phone home to New York.
"They're at work tomorrow," he said. "I'll let them know in the morning."
Sarah Trotto is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.