Eaton figured shouting an obscene number of expletives at the pitcher would definitely make him come back and pick up the Sharpie.
Romero continued to ignore the fan until he made a reference to steroids saying something to the effect of "How about you get me some juice," Eaton told the St. Petersburg Times.
"That apparently angered the player," police spokesperson George Kajtsa told the Web site.
Romero had been on a 50-game suspension for inadvertently violating the MLB's performance enhancing drug policy.
The pitcher returned, entering into a shouting match with Eaton before allegedly slapping him with an open hand. He filed a report with police who have since passed the case up to prosecutors.
Eaton was not injured and seemingly only filed the police report because he was "embarrassed because it happened in front of other fans and his family," Kajtsa said.
He called the incident very minor and believes the district attorney will focus on "more serious matters" a.k.a. real crimes.