NFL Does Not Approve

According to the Pioneer Press, the NFL has rejected the contract of Percy Harvin. The rejection will not keep Percy off of the practice field.
Typically, the violation relates to the way a team and agent structure the money of a deal, or language that violates the collective bargaining agreement. I am sure that we will find out what clause, the Vikes and his agent agreed upon that the NFL thought was out of line.

UPDATE

The NFL has approved Harvin's contract after the Vikes and Harvin's agent had to iron out the minor issue with the contract.