In an effort to shake his team out of a rut in which it has scored only three goals in three games, Washington Diiplomat Coach Gordon Bradley will shake up his lineup for toningt's 8 o'clock game at RFK Stadium with the Tampa Bay Rowdies.

Two players who started in Sunday's game against the Los Angeles Aztecs will be benched tonight. The Dips suffered a disappointing 2-1 defeat in front of 26,924,their largest crowd of the season.

One will be midfielder Rene Breevoort, who will be replaced by the now-healthy Sakib Viteskic. The other is likely to be either Alan Green or Paul Cannell, the Diplomat strikers.

The situation was complicated for Bradley yesterday when Green did not work out because of a case of the flu.

If Green cannot play tonight, Cannell will start up front along with Bobby Stokes, who worked in Green's place at practice yesterday. If Green is fit, Bradley seems likely to opt for a Green-Stokes front line with Cannell sitting out a game.

"I haven't yet decided what to do up front because I don't know what the situation is with Greenie," Bradley said yesterday. "I'll cross that bridge when I come to it."

Both Green and Cannell have been in a slump of late, Green going eight games without a goal and Cannell four. Even though he refused to be definitive on his plans, Bradley's tone yesterday seemed to be a tipoff.

"If you look back at the season, we've had our best games offensively when Stokes has played up front or right behind the front line," Bradley said. "So I'd like to see him move up from midfield.

"Alan's played very well of late. He's been creating chances for himself consistently. He just hasn't had any luck putting the ball between the posts.

"Paul's game is in the air. He's strongest with his head shot. Lately, though, he hasn't been winning the ball in the air.

Thus, it would seem that if Green can go, Cannell, the club's second leading scorer with 10 goals and six assists, will sit this game out. Jim Steele will move from defense to midfield

The game is an important one to the Dips, who are 17-9 for 151 points, good for second place in the National Conference East. The club has no realistic chance of catching the Cosmos, just a mathematic chance. The New York club is 29 points out front with four games left.

But the Dips are vying for playoff positioning with three clubs - Los Angeles, Vancouver and Minnesta. As things stand now, the Dips and the Aztecs will meet in the first round of the playoffs, since the Dips have the best second place record in the conference, and the Aztecs the second best.

The Dips lead the Aztecs by 16 points and a victory tonight, combibed with a Cosmos victory in Los Angeles, would virtually clinch the home field advantage for Washington. That would mean that the first game of the two-game series would be in Los Angeles, the second game in Washington. If the two games were split, the deciding 30 minute "minigame," would be at RFK, making the home field advantage significant.

Vancouver, the leader in the Western Division, and Minnesta, the leader in the Central Division, will become significant only if the Dips survive the first round. Currently, the Dips are one point ahead of Vancouver and have the third best overall record in the conference. The team with the fourth best record is likely to face the Cosmos in the second playoff round.

Minnesota is 15 points ahead of Washington, but the Dips have one more game to play than the Kicks. If the Dips were to overtake the Kicks, it would mean that the Cosmos would be the only team in the conference that would have the home field advantage in a series with the Dips.

The first three rounds of the playoff are two-game series. The Sept.8 Soccer Bowl, in Giants Stadium, is one game.

Tampa Bay comes to town with the best record in the American Conference, 19-7 for 163 points. The Rowdies are battling the Houston Hurricane for the best mark in the American Conference and currently have a two point lead.

The Rowdies will be hurting tonight, however, because leading scorer Oscar Fabbiani is home with a neck spasm problem apparently incurred Saturday night.

Fabbiani, the fleet Argentine striker, has 23 goals and seven assists for 53 points, second only to the Cosmos' Giorgio Chinaglia in the league. He also scored the game's only goal in the Rowdies' 1-0 victory over the Dips in Tampa June 9.

With Fabbiani out, the Rowdies' leading active scorer will be Rodney Marsh, "the Clown Prince of Soccer." The 34-year-old Englishman, who has 11 goals and 11 assists this season,announced Monday that he would retire at the end of the season.