Wayne Rooney Makes It Official With D.C. United, 'Let's Get To Work'

Wayne Rooney -- one of the most famous soccer players in the world -- has made it official ... he's joining D.C. United ... and his first game in the MLS is in TWO WEEKS!!

The team announced Rooney's arrival with a dope hype video ... titling it, "#NoWayneNoGain."

The ex-Everton star is a British legend on the pitch ... and his arrival has plenty of people gassed up for American soccer -- including Rooney himself, who says, "All right D.C. Let's get to work."

But, not everyone's as charged up about the move ... with Alexi Lalas telling TMZ Sports just a month ago that there's no way Rooney's arrival will "move the needle" when it comes to MLS interest.