Playoff fever has finally hit the North American Soccer League. As the Washington Diplomats into the last third of the season. Coach Gordon Bradley admits it is time to keep a watchful eye on the rest of the leagus.

"The final third of the season is the toughest," said Bradley. "Several of the teams have improved a great deal and others are now playing their best soccer. Right now in our conference (National), every team has a chance to make the playoffs. In the other one (American), several of the teams have already been eliminated. So you know it'll be tough for us."

The Dips will entertain the tough San Diego Sockers tonight at RFK Stadium at 8 o'clock in the first of what Bradley considers a must game if Washington is to make the playoffs.

"When we were 9-9, I told the team I wanted to be 12-9 before we went to Tampa (Bay)," said Bradley. "We wanted to win these three home games. We've won two but San Diego will be the hardest of the three."

Washington has bounced back after a disastrous six-game losing streak to win three of its last four matches. Both the offense and defense looked sharp at times in besting Los Angeles, 4-0, and Portland, 2-1, in the last two games.

Bradley was a bit miffed that the Dips missed a few golden opportunities to get a third goal and the max-imum nine points in their last outing. Those points are the single most important factor in deciding what teams will quality for the playoffs. The top two teams in each of the six divisions, three in each conference, qualify. In addition, two wild-card teams from each of the two conferences will qualify. Those four teams are selected on the basis of the highest number of points from among the teams that did not finish either first or second in their respective divisions.

The first round of the playoffs will match the division winner with the most points hosting the wild-card team in the same conference with the fewest. The division winner with the second-highest number of points will host the wild-card team in the same conference with the most points. The division winner with the least number of points will host the second-place team in its conference with the least number of points. The second-place team with highest number of points will host the second-place team with the second highest number of points in its respective conference.

The teams then advance to the conference semifinals, which will be contested two-game home-and-hom series. The conference champions meet in the one-game showdown, the Soccer Bowl at Giants Stadium in East Rutherford, N.J., Aug. 27.

Washington has all but conceded the Eastern Division title to the 15-3 Cosmos who have 132 points. The Dips, 11-9 with 98 points, are locked in a fight for second place with Rochester, 9-10 and 84 points, and Toronto, 9-9 and 79 points.

Teams receive six points for a victory and one point for each goal scored up to a maximum of three per game. Thus a team winning, 3-2 would receive the same maximum nine points as a team winning, 7-0.

"I'm very much aware of Rochester and Toronto, especially. We have two games with Rochester and one in Toronto and they will be very important," said Bradley.

Aside from those three games. The Dips must play in Tampa Baby (Saturday night), in San Jose and in Seattle. Washington's home games are against Philadelphia, New England and the Cosmos.

"I think if we win six of these final 10, we'd be in for sure," said Bradley. Washington can assure itself of a home playoff game if it finishes as the National Conference's second-place team with the highest number of points.

The Dips have been getting excellent play from wingers Ken Mokgojoa, who replaced injured Mike Bakic, and Ray Graydon, midfielder Cus Hiddink and defenders Tommy O'Hara, Ane Mihailovich and Jim Steele, when he can play.

Steele, the defensive leader, has been hampered by a groin injury and has seen limited duty. The sweeper will rest his injury tonight since he must sit out the game on suspension because of points accumulated by on yellow cards.

"We'll miss Jimmy because he yells and talks out there," said Bradley. "No one else does that. Gary Darrell will replace Jimmy and will do a good job but someone has to take the responsibility of running things. In practice, I worked with the first unit and I was the loudest one out there. But I can't play."

Hiddink, a Dutch first division player, has blended in well with the offense and provided the unit some stability and leadership.

"It wasn't hard to adjust," said Hiddink. "Once I talked with the guys up fron and found out where they want the ball, it was fine. In the midfield I want to create chances and keep the pressure on the other team. Sometimes we lose the ball too early and haven't been able to get moving. Movement is the most important thing. Give and go, give and go. I prefer a fast tempo, anyway."

San Diego, the American Conference's Western Division leaders with a 12-7 mark and 108 points, may tire against the Dips. The Sockers are in the midst of a seven-game road trip (12 thus far) lost two). However, San Diego is the NASL's biggest team physically.

They have several players 6-foot-2 or taller, including 6-5 defender Peter Nover and like to wear down opponets.

"We'll have trouble with them in the air. We can't give them too many corners or let them set up plays," said Braddley.

Jeans Willrich (17 points) is the Sockers' top scoring threat. Derek Smethhurst, once a member of the famed Murderers Row in Tampa Bay, was obtained from the Rowdies last month for added punch. Midfielder Julie Veee is the team leader.