Marlins manager Jack McKeon wanted to give the 22-year-old third baseman the day off Tuesday after hearing about his promotion and travel.
"That's not fair to the kid to put him in a spot," McKeon said. "You try to develop these guys -- not bury them -- and try to pick your spots. I'll get him in there tomorrow or maybe the next day. I want him to get his feet wet tonight. He may go in there for defense like I used [Donnie] Murphy last night. See how the game goes. Maybe I'll run him in there for an at-bat or something."
Of late, Greg Dobbs and Jose Lopez have split time at third base, with the latter starting with a left-hander on the mound.
McKeon said that Dominguez would bat either sixth, seventh or eighth in the lineup.
"Just depends how we're going," McKeon said. "We've got some pretty good hitters hitting low. I always looked at it, if you're one through nine you're all right. Doesn't make any difference where you're at."
Dominguez, who will wear No. 54, called it a dream come true to reach the Majors. He was Florida's 12th overall pick in the 2007 First-year Player Draft.
"Just go out and play well, be myself and have good at-bats and play good defense," Dominguez said.
During the 10th inning of Tuesday night's game, Dominguez made his Major League debut -- getting hit by a pitch on a 1-2 count -- as a pinch-hitter with one out.