Soccer BEEF!!!!
D.C United coach Ben Olsen clearly wasn't too pleased about Alexi Lalas' comments on Wayne Rooney -- because now he's throwing some shade of his own.
Earlier this week, Lalas told us he wasn't too pumped about the MLS team working on a deal with Rooney -- because the guy's essentially a has-been.
"For me, Wayne Rooney doesn't move the needle," Lalas said ... "It might fill some seats, but not that many seats."
Olsen tells TMZ Sports .