While the event was low-key by professional athlete standards, it was well attended and another sign that the former first-round pick is becoming a face of the franchise.
"One of the things we enjoy as players is being able to meet fans and get out in the community a little. It's something we embrace," Castro said. "Being right after the All-Star Break, it was nice to see so many people out there in support of not just me, but the team too."
Whether it's starring in "Which Wich" commercials locally, signing autographs or being recognized as one of baseball's elite, Castro is becoming synonymous with the Astros' rebranding and rebuilding effort.
It would seem a strange match, given that Castro is more a quiet leader and low-key personality than a gregarious figure.
But the Stanford product is widely considered among the team's nicest players and he's also shown initiative in the community.
Last month, he and his wife hosted the Castro's Kids Book Drive at Minute Maid Park to help supply the Houston Independent School District with more reading resources.
"I tell you what, if we're going to have a guy represent this team, I want it to be Jason Castro," said manager Bo Porter. "I've said this before; if I'm looking for someone to bat third and marry my daughter, it's him."
As for dealing with some of his new-found fame, the soft-spoken Castro said he's not shy about being a public figure.
"I'm fine with it. It doesn't bother me at all," he said. "It's part of being a good player. Hopefully, the better we play and the more this rebuild goes along, the more attention we will get. That's a fun part of it, not a burden. We need to get used to that."
Chris Abshire is an associate reporter for MLB.com.