"The law is fairly clear and consistent with Northwestern's position, so the NCAA has made no contacts with anyone in Congress attempting to ban the unionization of student-athletes," Osburn said.
Colter, however, called the decision a "strong ruling" and predicted it "will be hard to overturn."
The NLRB does not have jurisdiction over public universities, so the push to unionize athletes has been primarily targeted toward private schools such as Northwestern.
Rep. George Miller of California, the top Democrat on the House Education and the Workforce Committee, said after a meeting with the Northwestern group that "what they've drawn up here is a list of concerns that they have as athletes in Division I schools where there is clearly an imbalance in the relationship. And they're seeking the right to form a union for the purposes of putting some balance back in that relationship."