CHICAGO — Will the South Siders be playing baseball in the South Loop? According to the Chicago Sun-Times, “serious” negotiations have taken place between the Chicago White Sox and developer Related Midwest in regard to possibly building a baseball-only stadium at Roosevelt Road and Clark Street — an area known as “the 78.” Related Midwest owns the site, according to the Sun-Times, which also reported the Illinois Sports Facilities Authority — owners of Guaranteed Rate Field — has not been involved in the talks. Just where the Sox will be playing in the future has been a topic of conversation …