From the Tulane Sports Law Blog:
While section 1291 of the SBA exempts the NFL and other professional leagues from antitrust attack when pooling their broadcast rights, section 1293 takes away that protection in certain circumstances.vi Section 1293 was designed to protect college football gate receipts from the potentially devastating effects of competing for crowds against televised professional football games.College football is far, far from an amateur sport conducted among self-organized clubs and associations. It is big business with Congressional protection.
The SBA prevents NFL broadcasts from competing with college football attendance by removing the antitrust exemption granted in section 1291 when the NFL broadcasts games at times when college games are typically played. If the NFL and its broadcast partners were to televise any of the games sold in the pooled packages during the prohibited time frame, they would risk treble damages in the event those pooled packages are held to be in violation of antitrust laws.
Specifically, the antitrust exemption granted in section 1291 does not apply to any professional football game televised (1) between the hours of 6 pm Friday and 12 am Sunday, (2) beginning on the second Friday in September and ending on the second Saturday in December.
The first Saturday game played by the NFL for the 2011 season is on December 17th. It is the third Saturday in December.
Thus, while not a direct prohibition, the risk of treble damages is more than enough to keep the NFL at bay-not to mention that in today's marketplace it would not make much business sense to try and compete with college football broadcasts. After all, over the last 50 years, the football fan has become accustomed to watching college games on Saturday and professional games on Sunday.