It all started earlier this month when a fan named Sean Deitrick went on X to express displeasure about not receiving a baseball signed by Garcia, which he previously ordered from apparel giant, Fanatics (Garcia's signing was delayed, thus no ball).

Deitrick's mood ... "So, so bummed."

The tweet got enough attention that it made its way to the screen of Rubin, Fanatics founder ... and the management team.

A few weeks later, Sean provided an update, writing, "[Fanatics] was really nice and tried to help me get another ball, but I told them I already had one and figured that was that."

Cue the big surprise.

"Then, today, they surprised me with a DM from [Adolis Garcia]," he wrote on X, before saying, "I'm going to Opening Day!!! 🙏🙏🙏"

Sure enough, Fanatics reached out ... and was going to get the fan a signed ball, but he'd already found Garcia's John Hancock elsewhere. Rather than stopping there, Rubin and Fanatics wanted to do something special for the guy.

They reached out to the 31-year-old, 2x All-Star ... who then recorded a message for Deitrick, and sent it to him via direct message on social media.

"Hi Sean, Fanatics told me you're a big fan, and I can't wait to see you at the home opener at Arlington Stadium!"