The National Football League is only one-quarter of the way through its 1981 season, but the NFL Players Association is already talking tough about its contract demands for next year and laying the groundwork for a possible strike that could seriously disrupt the 1982 season.

"I don't see the owners giving us what we want without some type of collective action," said Gene Upshaw, the 15-year lineman for the Oakland Raiders and the president of the NFLPA. "The owners are preparing themselves for the worst, and I think the players should, also. We're going to urge the players' wives to salt some money away for what could be a strike year."

Citing this year's seven-week, midseason baseball strike as an example, the football players say they have no intention of repeating their 1974 tactic, when they struck during the preseason.

"The baseball strike has helped us immeasurably," said Ed Garvey, executive director of the NFLPA. "It is a good example for the NFL players of what can be achieved if they can stick together. The crucial thing about the baseball strike is that it occurred during the season. Then you can't hire scabs. I can't imagine another training-camp strike."

Although the NFLPA's contract with the owners does not expire until next July 15, the union has already prepared and distributed to its members a booklet setting forth its demands, a package hammered out at a meeting of player representatives from each of the NFL's 28 teams this summer in Chicago.

The package represents a major shift in emphasis away from individual contract negotiations to a system in which all players would share in a fixed percentage of gross revenues generated by the NFL. For their next contract, they are asking for 55 percent and would distribute the money according to a formula based on number of years in the league and position.

But it has met a wall of opposition from the owners.

"Philosophically and conceptually, it's just not an acceptable alternative," said Jack Donlan, who heads the NFL Management Council, the panel that negotiates with the union on behalf of the owners.

"These owners believe that once you go to a percentage, any percentage, you're going to have joint control. That's a departure from the owners' standpoint. It makes an employe your partner, and we consider the players to be employes. The owners feel that they are the ones who have made this league grow."

Whether or not the union is strong enough to stage a successful strike and enforce its demands is a question that remains to be answered. A potentially divisive effort to unseat Garvey failed at the summer player-representatives' meeting, but there are some who feel the scars of that battle remain and that the union was left weakened.

"It obviously has damaged the union somewhat. I would try to make the change again, but it's over with now," said player-representative Keith Fahnhorst of the San Francisco 49ers, one of seven dissidents to vote against Garvey. "We pledged our support to Ed, not to get back in the fold but because we knew we'd hurt the union more if we kept pursuing it. We have to direct our energies against management in the upcoming negotiations."

Predictably, Garvey and Upshaw downplay the significance of the ouster attempt. "There were some personality differences; a difference of opinion about what we ought to be doing," said Garvey. "You'd like things to be totally unified. But I don't think in any democratic organization you can expect monolithic agreement. We were unanimous in making a percentage of the gross our No. 1 priority in our negotiations."

Leading the revolt against Garvey were two former NFL players who had remained active in the union, former Washington Redskin center Len Hauss and Bob Moore, former Oakland Raider tight end. Moore resigned as the union's Western director and Hauss resigned from its executive committee following the unsuccessful attempt against Garvey.

"I think we came out of that meeting with the union stronger than it was before we got rid of Hauss and Moore," said Upshaw. "Ed Garvey has given his heart and soul for the union."

Argued Moore, "We felt one of the problems in the union was that all of us were spending too much time defending Ed Garvey and not enough time defending the program. He has always been a controversial director, but I think now things are breaking down on pro- or anti-Garvey lines. I think percentage of gross is a good concept, but a lot of players do not believe that is right. And a lot of players don't believe in a wage scale. They say it smacks of socialism."

Said Hauss, former NFLPA president, "The basic purpose of the union is to look after its players. But Garvey seems to be working towards a strike. He's only interested in a percentage of the gross. He wants to achieve some kind of revolutionary breakthrough."

Mark Murphy, player representative for the Redskins, said most of his teammates and player representatives from other teams support the union demands for a percentage of the gross and a wage scale.

"But we're interested in other things, too," said Murphy. "Job security, protection from injury, freedom of movement . . ."

In describing union demands, Garvey does not use such terms as "revolutionary," but he leaves no doubt that what the union wants is a radical departure from the status quo.

He maintains that football is easily the nation's most popular professional spectator sport, yet salaries lag far behind those in other pro sports. The average NFL salary in 1980 was just under $80,000, which was $28,000 less than a professional hockey player could expect to earn, $90,000 less than a baseball player and $106,000 less than a basketball player.

"Individual contract negotiations in the NFL haven't, don't and won't work to benefit the majority of our members," argued the union in the booklet describing the contract demands.

The reason, said the union, is that NFL teams regularly fill their stadiums, share television revenues equally and divide the proceeds from postseason playoffs and Super Bowl games. Because their stadiums are already full and their TV packages assured, the owners have no economic incentive to raid other clubs for superstars to draw larger gates.

"They have no economic incentive to win," said Garvey.

Retorts the NFL Management Council's Donlan, "That's clearly nonsense. The average NFL club spends $750,000 a year on scouting. Why would they do that if they weren't interested in getting the best players? They could just have the league set up a scouting department and read their reports."

Donlan also disputed Garvey's assertions that the NFL franchises are unusually lucrative investments.

"A guy like Jack Kent Cooke could invest his money somewhere else and make a lot more on it than he could on a football team. From a businessman's standpoint, this isn't something to write home about. These guys don't make their money in football, they make it somewhere else. They spend it in football."