Goodell said Wednesday night that a former federal judge picked by the commissioner and the players' union to lead the arbitration will ultimately decide its rules.
Goodell says he doesn't think testifying is his decision and it's not something he's addressed.
The union is appealing Ray Rice's suspension for violating the NFL's personal conduct policy. The former Baltimore Ravens running back was suspended after video of him hitting his then-fiancee in an elevator was publicly released.
Union officials said in announcing the appeal that Goodell and his staff would be essential witnesses.
The appeal will be heard by former U.S. District Judge Barbara S. Jones.