The war of nerves ends here today when West Germany, the World Cup holder, opens the 1978 tourament by meeting Poland at the River Plate stadium.

The usual games of poker have been played. Key men are said to have been injured: then miraculously to have recovered. Three poles, among them the huge goalkeeper. Jan Tomaszewski, a hero in 1974, were said to be doubtful, although all now seem likely to play.

The West Germans, accustomed to disagreements over center-forwards, have another on their hands. In Mexico eight years ago, the choice lay between the veteran battler, Uwe Seeler, and the young opportunist, Gerd Muller, Helmut Schoen, the coach, who will retire after this World Cup, resolved that by using them both.

Now, there are rival claims for Klaus Fischer, the muscular, acrobatic Schalke 4 club striker, and Dieter Muller, who scored three goals in an astonishing first game when he came in as a substitute in Belgrade against Yugoslavia in the European Nations Cup two years ago. Schoen may again resolve the problem by using them both, but since he has never done so before, and it would mean excluding a right-winger as potentially dangerous as Rudi Abramczyk, it seems a slightly dangerous compromise.

The game may be resolved by the performance of two young men in midfield, 20-year-old Hansi Muller of West Germany and 21-year-old Zbigniew Boniek, the red-haired Pole. A few months ago, Muller seemed to have little chance of gaining a place on the West German team, but the squad's problems in midfield have been so great that Schoen was forced to push him in at the deep end. He is a clever, left-footed player.

Boniek is also a left-footer, one of the few new men to emerge since Poland make its fine showing in the last World Cup. With him in midfield will be the incomparable Kazimierz Deyha and the effective Henryk Kaspercza.

What Poland no longer has is the deadly combination of two wingers. Grzegorz Lato is still with the team but Robert Gadocha is now in the United States. Whatever happens today, however, it is most unlikely either team will fail to qualify in a bizarrely unbalanced group completed by Tunisia and Mexico, although the Tunisians looked to be a much-improved team on its recent visit to Europe.

Tomorrow, Argentina, increasingly optimistic, will play Hungary in Buenos Aires. "Uncle" Lajs Baroti, the veteran Hungarian coach, says he isn't worried by the team's recent 4-1 defeat by England at Wembley: "They were afraid of being injured before the World Cup." Perhaps, but they looked to be a poor team that day, and unless Hungary gets a great deal more out of its tall, talented but somewhat indolent young midfielder, Tibor Nyilasi, it will find life hard against Argentina, who is specially strong up front and in midfield.

Bad news for Argentina was an injury to left foot of its splendid little right-winger. Rene Houseman, a fine Performer in 1974, although if he isn't fit , it will have plenty of cover. Argentina will be hoping for goals from Mario Kempes, another 1974 player who, like Houseman, was then only 19.

The dilemma of where to play Kempes, the leading goal scorer in the Spanish championship, was resolved by putting him on the left side of the front line, in preference to two gifted left wingers, Daniel Bertoni and Jose Ortiz, thus leaving the left midfield position to be contested by the fragile, gifted Daniel Valencia, the probable choice today, and the sometimes spectacular Norberto Alonso, who has been in excellent form in recent weeks.

The Dutch do not play until Saturday, when they meet an Iranian team that seems certain to be without Hassan Rowshan, its best and fastest striker, in Mendoza. There is still a great deal of disagreement over the chances of the Dutch. Pessimists say that there is chance of the team transcending the loss of Johan Cruyff, Wim Van Hanagem and other stars. The optimists say that the tactics of Ernst Happel, the Austrian who coaches Belgium's Bruges club and once won the European Cup as coach of Holland's Feyenoord, is going to produce a remarkable combination.

Certainly, there is great tactical interest. It looks as if Happel intends to play no fewer than five men in midfield, two lying deep, one in the center and two farther forward. The role of the middle went to the 34-year old Van Hanagem in Austria, where The Netherlands recently won, 1-0, but Happel wasn't satisfied with him. After the game, he told him he would not automatically be a starter. Van Hanagem, who was Happel's star and lieutenant with Feyenoord eight years ago said that, in that case, he would prefer not to go to Argentina.

It looks as if Aarie Haan, an Anderlecht of Belgium player, will be the man in the middle, and that the two strikers will be two more survivors of the brillant 1974 team, Johnny Rep and Rob Rensenbrink who, at 31, is expected to be the star of the Dutch team. Rensenbrink is a winger of great versatility who feels he will play better without the overshadowing presences of Cruyff and Van Haanagem.

The Italians, who will play tomorrow in Mar del Plata, are weary, especially Mario Tardelli, the little midfield player who will have to guard France's star, Michel Platini. The attack will be led by the "Six-Million-Dollar Man," Paola Rossi, but Rossi, although he's livelier than Roberto Graziani, is very inexperienced in international competition. France, says it is uncertain about its team, with injuries to Marius Tresor, their irreplaceable black sweeper, and Dominique Bathenay, its only really strong midfield man