There's a ballpark right now. It's where the Brooklyn Cyclones play, in the NY-Penn League. While they have seating for only a minor-league sized crowd, it looks obvious where the rest of the stands could be added - they need to finish tearing out one street. I thought I read somewhere long ago that it's a MLB site in waiting. Fun place to spend an afternoon and then go to a night game, etc. https://www.google.com/maps/place/Brooklyn+Cyclones+at+MCU+Park/@40.5748057,-73.9844943,715m/data=!3m1!1e3!4m5!3m4!1s0x89c245cae7316bf3:0x6c2876836bb13f45!8m2!3d40.5748057!4d-73.9844943?hl=en