Manchester United manager Sir Alex Ferguson came all the way to Red Bull Arena Tuesday to promote his team’s appearance at Major League Soccer’s All-Star Game there this summer. And he made it sound as if the venue, and not the storied English club, was the headliner. “I must say I’m very, very impressed. I think this is a real football stadium,” Ferguson said. “Sometimes you go abroad and you have these huge tracks separating the football field from the spectators. To me, that’s not a real football stadium. “Stadiums like (at) Manchester United, Liverpool and Everton, and here we see with the Red Bulls, the fans are right on top of you. It creates a fantastic atmosphere.” Commissioner Don Garber must agree, as MLS chose to stage the July27 game at the oval in Harrison, N.J., even before securing Man U as the all-stars’ opponent for the second straight summer. Last July, United drilled the MLS side, 5-2, before more than 70,000 raucous fans at Reliant Stadium in Houston. Garber said hosting Man U at Red Bull Arena, with its modest 25,000 capacity, means that far fewer tickets can be sold than at, say, New Meadowlands Stadium, where nearly…