No matter, the five first pitches went off without a hitch.
Following a presentation of the flags by the Vandenberg Air Force Base, Rubalcaba, Hasan, Master Sergeant Jennifer Johnson (Air Force), Major Michael Hastings (Army) and Petty Officer Beau Roper (Coast Guard) made their throws in front of an applauding sold-out crowd at AT&T Park.
Their battery mates were Matt Cain, Alex Hinshaw, Jack Taschner, Travis Denker and Barry Zito.
"It's been a family tradition to watch the Giants on television my whole life," said Rubalcaba, who is currently stationed at a Navy operations center in San Jose, Calif., as an instructor and spent nearly a year in Iraq between 2007-08. "This is actually like a dream come true."
The veterans were joined on-field by assorted family members, 23 in all. Many of them wore Giants apparel, including Johnson's children.
Currently working in aviation resource management, Johnson has been deployed three separate times to Turkey, Romania and Africa. A Moffett Field, Calif., resident (an hour away from AT&T Park), Johnson said her kids are all Giants fans.
For her, it was exciting to get on the field and an honor to be so warmly received by the fans.
"I'm actually ecstatic to be here today," Johnson said. "It's just a pleasure to see everybody standing up and cheering the military, knowing that they care about what we're doing."
The people in the stands weren't the only onlookers. For a day, the Giants players were fans, too.
Outfielder Dave Roberts, the son of a retired Marine, said inviting the veterans to the park was an appropriate way to celebrate the national holiday. It "makes sense" that they got to share the field with the players.
"It's awesome to honor these people," Roberts said. "I think for us Americans to acknowledge what they are doing is the right thing to do."