With a player strike Tuesday all but a certainty, National Football League management and the leadership of the NFL Players Association were making contingency plans today for a walkout, which would be the first regular-season strike in the NFL's 63-year history.

Ed Garvey, executive director of the NFLPA, said the players for the 28 teams in the league will hold team meetings Monday night following the meeting here Monday afternoon of the union's executive committee. The committee is expected to call a strike effective Tuesday morning in the aftermath of the collapse of contract negotiations here Friday night.

The first game affected will be Thursday night's nationally televised contest between Kansas City and Atlanta.

Garvey has said union player representatives on the teams have assured the NFLPA of almost 100 percent participation in the strike.

Meanwhile, Jack Donlan, executive director of the NFL Management Council, the league's labor negotiating arm, said today that management will keep its options open as long as possible on what contingencies to pursue in the event of a strike.

"Right now, it's all by guess and by golly," Donlan said. One option under consideration is attempting to put on games by using free agents and players who defy the union. But Donlan said management will likely wait to see what actually happens in a strike before deciding what to do.

"I think we will be looking at it on a day-to-day basis," Donlan said. Technically, any decision on whether or not to play in the event of a strike would be made by the seven-member executive committee of the management council.

But that committee will be guided in large measure by the recommendations of the NFL competition committee headed by Tex Schramm of the Dallas Cowboys, according to Donlan.

In Dallas today, Schramm told the Associated Press he doesn't think the NFL will attempt to play with a roster of free agents who had been cut during the preseason. Television networks were understood to have told the league they have no interest in televising games that are not of normal NFL caliber.

Schramm also said, "From what I've been told, there are no plans to make up any games. Of course, it depends on how long the strike is."

If a strike forces cancellation of two games, Schramm said, the NFL would simply play a 14-game schedule as it did through 1978.

If four or more games are lost to a strike, Schramm said, they would have to be made up "to preserve the integrity of competition."

NFL Commissioner Pete Rozelle told the Chicago Tribune that insofar as it's possible, a poststrike schedule would have teams playing teams within their division so that there can be division champions for postseason play.

As of tonight, there were no talks scheduled or planned between the two sides before the meeting of the union executive committee Monday at 2 p.m.

Negotiations collapsed Friday when management turned down a union offer that moved from a demand that players receive 55 percent of the NFL's gross income to a demand that they receive 50 percent of the league's $2.1 billion television contract.

The proposal also demanded that the television payments be supplemented by payments of similar, although slightly less, amounts from the clubs, and Donlan denounced the plan as "in effect, 100 percent of the television contract."

The players had also sought establishment of a trust fund to pay players on a seniority-based scale with performance-incentive bonuses. Donlan turned that down, too, saying the owners preferred the current system in which players negotiate their contracts individually.

Garvey said that move was tantamount to "throwing down the gauntlet and saying take the current system or else."