Tucson Padres right-hander Sean O'Sullivan was called up Wednesday morning to pitch Friday night for the San Diego Padres against the San Francisco Giants.


When he was in third grade at Rancho San Diego Elementary in El Cajon, Calif., Sean O'Sullivan stood up in front of his class and made a declaration.

"I'm going to be a professional athlete," O'Sullivan told his classmates. "And I'm going to play for the San Diego Padres."

The first part came true in 2006 when he made his minor- league baseball debut as an 18-year-old in the Los Angeles Angels system. The dream got even better three years later when the Angels promoted him to the big leagues.

This Friday night at Petco Park in San Diego, the second part will finally come true - and it will be the sweetest moment of them all.

O'Sullivan, who grew up in the San Diego area, dreaming of wearing a Padres uniform, will start for San Diego in his first appearance in the big leagues since 2011.

"I didn't just dream of playing in the major leagues," O'Sullivan said. "I dreamt of playing for the San Diego Padres. I always thought about how cool it would be to wear that Padres uniform.

"It's been a long time coming."

O'Sullivan, 25, was informed Wednesday morning by Tucson Padres manager Pat Murphy that he was going up to start San Diego's Friday night game against the San Francisco Giants.

"You don't have favorites, but this is what is really good about the game," said Murphy before Tucson's 6-5 loss to Tacoma on Wednesday night at Kino Stadium. "Even though we're losing our horse for good, it's a good day. I'm really, really excited for him.

"He's a great kid and a great teammate."

O'Sullivan came up with the Angels and was traded to the Kansas City Royals in 2010. He played for the Royals in the majors in 2010 and 2011, but didn't have much success, going a combined 5-12 with an ERA of 6.63. He opened the '12 season with Kansas City's Triple-A team in Omaha, Neb., and then was traded to the Toronto Blue Jays later that season, where he remained in the Pacific Coast League with Las Vegas.

After the season, he became a free agent and signed a minor-league deal with his hometown team.

When he walked into the clubhouse on the first day of spring training, he took pictures of his uniform, sent them to everyone in his family and had to pinch himself that he was officially a member of the Padres organization.

The decision to sign with the team that he grew up rooting for turned out to be one of the best choices of his professional career. In 18 starts with Tucson this season, O'Sullivan went 7-4 with a 3.88 ERA in 102 innings. He struck out 90 batters and walked just 29.

"I've worked very hard this last year and a half or so," O'Sullivan said. "I wasn't real happy with the way I pitched previously in the big leagues. My last year with Kansas City didn't go the way I wanted it to. I've been anxious to get the opportunity to prove that I'm not that guy and I'm someone that can help a team win at that level."

Though, believe it or not, getting called up by his favorite team likely won't be the best thing that happens to O'Sullivan this month. His wife, Sabrina, is 8 1/2 months pregnant with the couple's first child.

"It's going to be a very interesting few weeks for me," O'Sullivan said. "It works out well that the (All-Star) break is coming up. Hopefully she doesn't go into labor on Friday night."

Even with the loss of O'Sullivan, Tucson will still have a strong starting rotation going forward. Four starters - Burch Smith, Robbie Erlin, Anthony Bass and Tyson Ross - all have big-league experience this season. The team's fifth starter, Matt Andriese, has a 2.50 ERA in Triple-A in three starts.

But O'Sullivan's leadership and ability to go deep into nearly every game he starts will certainly be missed. The right-hander is out of minor-league options, so he likely won't return to Tucson this season.

"The career of a professional athlete is so short," O'Sullivan said. "You want to make sure you maximize the time you get. I love the game of baseball and I've always wanted to play at the highest level."

¡Tus Padres!


• What: Padres at Las Vegas

• When: 7:05 p.m.

• Radio: 1290-AM

Tacoma 6, Tucson 5

• Highlight: Rainiers starter Brian Sweeney pitched 6 1/3 innings to earn the win and improve to 8-3 and Tacoma took the three-game series from the Padres (51-43) two games to one. Tucson trailed 6-2 through six innings and scored two in the seventh and one in the eighth, but couldn't tie it in the ninth as Logan Bawcom locked down the save. The Padres did bang out 13 hits in the loss.

• Big number: 6: Rehabbing first baseman Yonder Alonso had two more hits for Tucson and is now 6 for 11 in three games with the Padres.

• Tonight's starters: RHP Anthony Bass (2-2, 7.02 ERA) vs. RHP Rafael Montero (1-2, 4.65 ERA)

- Daniel Berk