Weeks after the Guardian’s Steven Wells checked out the phenomenon that is Sons Of Ben, the worst kept secret in American’s 6th or 7th most popular professional sports league was confirmed yesterday. From the Philadelphia Inquirer’s William Bender.

After months of speculation and political wrangling, Major League Soccer announced that, in 2010, Philadelphia will become its 16th team, playing in a 20,000-seat stadium to be built on the Chester waterfront.

The team, which will be named with fan input, already has an unprecedented level of support for an expansion franchise, said MLS commissioner Don Garber. And it would likely alter the dynamic of the I-95 rivalry between New York and D.C. United – perhaps siphoning some South Jersey fans in the process.“I live in New York and I know what it’s like for Giants fans to attend a game at the Linc,” Garber said. “I know what it’s like to be a Mets fan and try to go down and attend a Phillies game.”

Wait until Red Bull fans meet the Sons of Ben in Chester.

“There’s already some animosity between their supporters club and our people,” said Dan Ryazansky, who runs MetroFanatic.com, a site frequented by the Empire Supporters Club and other New York soccer fans.

“I’ve never seen this level of interest from the public sector, never have had a supporters’ group the size of Sons of Ben before a team’s ever launched,” Garber said after yesterday’s announcement at the Wharf at Rivertown, which adjoins the Chester stadium site. “I think there’s something very special being incubated here in Philadelphia for Major League Soccer.”

Former Tampa Bay / Metro Stars executive Nick Sakiewicz has been installed as the club’s first CEO, and while he’s unquestionably qualified for such a position, Philly Phans might well gaze longingly at the star power another MLS franchise has brought to the boardroom. Sure, Sakiewicz knows the league, but how does he look in fishnets?