The National Football League owners are gearing up for expiration of the collective bargaining agreement with the players in July 1982 -- and setting up a reported gag rule and strike fund similar to baseball's.

In executive (secret) session last week in Detroit, says Will McDonough of the Boston Globe in a copyrighted article, the NFL owners "agreed to muzzle themselves or pay the consequences. The consequences could amount to a $100,000 fine for any owner or front office executive who talks too much" about the upcoming battle. That compares with the $50,000 baseball socked Milwaukee exec Harry Dalton for making print with conciliatroy remarks.

And, McDonough adds, "they voted to accept a $150 million line of credit from a California bank to be used in case of a strike. Each team would be entitled to borrow up to $5 million against this in case of a general strike." Baseball management, it's said, has only $50 million strike insurance.

Pro football might have installed the gag rule immediately, but the Oakland Raiders, of all people, cited a provision of the league constitution and requested a 14-day delay to study the idea, under which any official with a statement on labor relations must clear it with John Donlan, executive director of the NFL Management Council. Now, they'll likely vote the rule in on June 17.