One month ago, when the Washington Diplomats were riding the crest of a six-game winning streak, Johan Cruyff was asked about an upcoming three-game road trip.

"Now," said Cruyff, "we find out."

He was wrong. The Diplomats still are unsure whether they are a middle-of-the-pack mediocrity, as they appeared to be the first half of the season,or a legitimate Soccer Bowl contender, as they often seemed to be in the second half of the season.

Now, beginning in their first round playoff game tonight at 8 p.m. in RFK Stadium against the Los Angeles Aztecs, they will find out.

They will find out whether Cruff, named yesterday "Star of the Year" by the Professional Soccer Reporters Association, can rise to the occasion against his ex-teammates and his longtime coach and be the leader and catalyst he must be if the Dips (17-15) are to upset the Aztecs (20-12) in this best of three (including minigame) series that will conclude Saturday in Pasadena, Calif.

They will find out if they can pull together in the absence of leading scorer Alan Green (knee), Juan Jose Lozano (calf), Thomas Rongen (ankle), and Sakib Viteskic (leg muscle) and beat a healthy team.

Finally, they will find out if, after seven years in existence, they are ready to win their first palyoff game.

In the NASL playoff system, the lower-seeded team plays the first game at home, with the higher seed playing the second game and the minigame, if necessary, at home. That means lower seed almost must win the first game to have any chance, since it is unlikely to win on the road after losing at home.

The Dips must be the aggressors tonight, and Coach Gordon Bradley says they will be.

"I think everyone -- Johan, the entire team -- knows what we have to do," Bradley said. "We all know the importance of home field in a short series like this. You just can't afford to lose the first game. It doesn't mean you can't win but it certainly makes it a lot more difficult."

That is putting it mildly, particularly when one realizes the Dips were 13-3 at home and 4-12 on the road during the regular season.

"The pressure is on us in this one the same say it was on them in the opener out there last year." Bradley said. "They have everything to gain and not much to lose. We'll be prepared."

The atzecs will also be prepared. One of the reasons they were so successful during the season was their preparation.

"When it comes to tactics," Cruff has often said of his old coach, Rinus Michaels, "there is no one in the world better." s

Michels, who says he wants to return to Europe next season, coached Cruyff in Holland, Spain and on the 1974 Dutch World Cup Team. The only time he has coached against him was the first half of the Aztecs' 2-1 win in Pasadena July 4, Cruyff left the game at halftime with the score tied 1-1.

"I would rather not coach against him," Michels said. "He is as good as any player there has ever been. He plays with his head, not just his body.

"But, we have a saying in Holland. He is like everyone else. He has a mother and he has a father. He is superb, but he is human like everyone else."

The Dips are hoping that Cruyff will play above the level of mere mortals -- as he did the second half of the season -- against Michels' team.

Atzecs have just the kind of balance that Cruyff has been complaining the Dips lacked all season. They have a superb goal scorer in Luis Fernando (28 goals); a threat in the air in 6-foot-3 Leo Van Veen, a solid midfield and an outstanding defense.

"I think there are six teams in the playoffs in our conference that we are better than," Michels said. "The Cosmos have the edge in individual talent and skills, but that is not always enough. we are a good team, an orgainized team."

To the Dutch, organization seems to be the next thing to godliness, Cruyff, Wim Jansen and Thomas Rongen, Washington's Dutch connection, talk of organization constantly.

To a certain extent, organization, will decide this series. "We've got to avoid careless errors," Bradley said. "In the playoffs, one mistake can decide a game."

"Last year, Johan was the difference between the two teams, no question about it. I expect him to be the difference again this year."

Last year Cruyff ended the series with a 50-yard dash to the goal in overtime for the winning score. The Dips would like nothing better than a repeat performance.

The "Star of the Year" award Cruyff won is based on points from individual star of the game voting. He was a runaway winner, with Los Angeles' Fernando second . . . Rongen trained yesterday for the first time since hurting his ankle 10 days ago and is listed as possible for Saturday's game . . . Becuase of all the injuries, Kenneth Mokgojoa may dress tonight for the first time since being injuried June 15 . . . Ticket sales have been brisk and if the weather is good the Diplomats are hopeing for a crowd approaching 25,000 tonight.