The Brief Upper Merion supervisors plan to build a $200 million sports stadium in King of Prussia, converting a vacant 17-acre office park into a multi-use sports and concert venue. Project leaders tell FOX 29 that they plan to attract a minor league baseball team and a professional women’s soccer team. Upper Merion supervisors plan to build a $200 million sports stadium in King of Prussia, converting a vacant 17-acre office park into a multi-use sports and concert venue. Project leaders tell FOX 29 that they plan to attract a minor league baseball team and a professional women’s soccer team. In a statement provided to FOX 29, Upper Merion Township Supervisor said that he "remains excited about the possibility of minor league baseball and professional soccer in King of Prussia."