NEW ORLEANS -- NFL commissioner Roger Goodell says he believes there will be an agreement soon with the players' union for testing for human growth hormone.

At his annual state of the NFL news conference Friday, Goodell said he expects an agreement for the tests to be reached in time for the start of the 2013 season.

Goodell noted that the league and union agreed to the testing two years ago in the collective bargaining agreement. He said it is important to have testing to retain the integrity and the brand of the league.

A few obstacles remain, however, before an agreement can be reached.

The NFL has finally agreed to allowing a neutral arbitrator to hear arguments on disputed tests, but the league has resisted a union proposal to allow players to introduce independent scientific testimony in those hearings to dispute a positive test.

Also, for the union, blood testing on game days is a non-starter and there remains some resistance over blood-testing on the day after games.

Information from ESPN senior NFL analyst Chris Mortensen and The Associated Press was used in this report.