Goodell cited a drop in television ratings for the league's recent draft as well as a reduction in traffic on the NFL's Web site as evidence that people are paying less attention to the sport. His remarks came at the end of the league's spring meeting.
The lockout, in its 11th week, has been allowed to continue by the 8th Circuit Court of Appeals pending a ruling by that court on the legality of a decision by owners to stop all player-related activity. A hearing is scheduled for June 3 to determine whether the lockout will become permanent.
Owners chose to lock out players after the NFL collective bargaining agreement expired with no new one having been negotiated to take its place.
"The longer (the labor impasse) goes, the more damage is done to the game," Goodell stressed. "We made this point back in March. It becomes more difficult when you get into litigation and that has proven to be true.
"Unfortunately, we're not negotiating. Any time you're talking it's a positive. I'd welcome any communication."
Goodell said owners had not made a determination as to when the start of training camps would be delayed and exhibition games would be canceled.
"We don't have a date, but that time is coming," Goodell said. "We're getting close to where we'll have to take (deadlines) into consideration."