NEW YORK (AP) - NFL Commissioner Roger Goodell says possibly using replacement referees for regular-season games is worthwhile to ensure long-term improvements to officiating.

The league and the NFL Referees Association have yet to reach an agreement, and Goodell acknowledged Thursday that time was running out to strike a deal that would make the regular officials available for the openers.

Goodell says the officials probably need a week to 10 days to prepare for the season, and the first game is Sept. 5, 13 days away. The first full Sunday of games is Sept. 9.

Goodell says of the replacement refs: "We think they'll do a very credible job."

Goodell spoke at a fantasy football event in Times Square.