The NFL's labor talks with its referees toward a collective bargaining agreement reportedly will go to federal mediation.

The league and its referees association have agreed to allow the Federal Mediation and Conciliation Service to help negotiate their labor talks, the Washington Post reported Friday.

The deal between the association and the NFL ends this month. Both sides have said there isn't one issue holding up the deal. NFL Referees Association executive Tim Millis recently denied the sides were at an impasse.

The league has begun looking for replacement referees should the sides fail to make a deal, according to Fox Sports. The NFL last used replacement referees at the start of the 2001 season.

The FMCS previously mediated the negotiations between the NFL and the players' union before the players were locked out during the 4 1/2 -month impasse last year.