The Washington Diplomats flew to Los Angeles yesterday, for a two-game opening round playoff series against the Los Angeles Aztecs that begins in the Rose Bowl Wednesday night.They were extremely confident about the playoffs, despite Sunday's 5-4 loss to the Cosmos.

"I'll bet all my wages we beat them," said Paul Cannell, sticking to an earlier statement. "We've got a better side than they do. It's as simple as that."

The Dips and Aztecs will play one of eight first-round playoff series. The second game of the series will be at RFK Stadium Sunday at 2:30 p.m. If the teams split the two games - regardless of goal differential - a 30-minute minigame will decide the series. If the minigame (which is not sudden-death) is tied, the series will be decided by a shootout.

The Dips' second opponent if they defeat L.A. is unknown because second-round opponents are determined on the basis of standing points.

The Dips finished with the fourth highest point total in the National Conference. That means that if the seedings hold through the first round their second opponent would be the Cosmos. But if one of the three teams seeded ahead of them - the Cosmos, Minnesota or Vancouver - loses in the first round, the Dips would move up a notch and play someone other than New York.

Washington Coach Gordon Bradley hopes to have his entire team available Wednesday night. Jim Steele, Don Droege and Bobby Stokes, who sat out the Cosmos game with suspensions, will be available as will defender Bob Iarusci, who sat out Sunday with the flu.

The Aztecs, who finished 18-12, are led by superstar Johan Cruyff, who almost single-handedly beat the Dips, 2-1, in RFK Stadium last month. The Dips defeated Los Angeles, 3-2, in overtime in the Rose Bowl June 30.

"We want to beat them very badly," said Bradley. "We lost to them in Washington and we thought we were better than they were then. We feel if we play our game we can play with anyone in the league - including the Cosmos."

If the Dips get by Los Angeles it seems likely that they will get a chance to try and prove they can play with the Cosmos in the second round.

The playoffs will begin tonight with Houston, the top seed in the American Conference, traveling to Philadelphia. The other American Conference pairings, with the higher-seeded team listed first, are: Tampa Bay-Detroit, San Diego-California and Fort Lauderdale-Chicago. The National Conference pairings are: top-seeded Cosmos-Toronto; Minnesota-Tulsa and Vancouver-Dallas.

Alan Green's three goals and an assist Sunday enabled him to break two of Cannell's club records. His 16 goals were two more than Cannell scored in 1978 and his 41 points were six more than Cannell had the same season....Bill Irwin surrendered 11 goals in his last three games, hiking his goals-against average from 1.17 to 1.45.... The Dips and Cosmos played 210 minutes of soccer to a 6-6 tie this season and were separated only by two goals in shootouts...Green had five of the six goals Washington scored against Cosmos.