The park, which was unveiled during the weekend, hosted an exhibition game Wednesday and fans said they were upset to discover there were only 6,000 on-site parking spots for the 37,000-seat venue, The Miami Herald reported Friday.
"The parking situation really stinks," fan Danny Pou said.
Marlins fan Orlando Aloma said he missed the first half-inning of Wednesday's exhibition game against Florida International University and he expects the situation to get a lot worse once an event with more than 15,000 attendees takes place at the ballpark.
"It's going to be terrible," he said. "I think people will have serious problems, unless they buy pre-paid parking."
Art Noriega, who directs the Miami Parking Authority, which oversees city-owned parking garages, said part of the problem was a lack of awareness among fans of the trolley service offered to and from the city garages.
"It's part of the learning curve," Noriega said.