Washington Diplomats Coach Gordon Bradley didn't bother to scout tonights's North American Soccer League opponent, the Colorado Caribous. Four of the expansion team's starters, including Dave Clements, the player-coach, either were signed by or played for Bradley when he coached The Cosmos in New York last year.

The interconference match at RFK stadium begins at 8. It will be broadcast on WTOP-1500.

"I know most of them well, and for that reason I expect a tough, fastpaced game," said Bradley. "I signed Dave in England a couple of seasons ago. When he left the Cosmos, he took several players with him to Colorado. He was a competitive player so I know he's a competitive coach. Some of those players are very skillful."

Two of the Caribous who most definitely will draw some attention are forwards and Bradley-products Jomo Sono, he hoped-for successor to Pele, and Brian Tinnion.

Tinnion has two goals while Sono, an excellent one-on-one magician from South Africa, has one goal. Another Bradlee signee, Bob Rohrback, has scored three goals for the Caribous, who are 2-4.

Carl Strong, an all-met player form Annandale High, is a reserve mid-fielder for Colorado.

Although Colorado has talent at some key positions, the first-year club has glaring weaknesses, especially on defense. American Greg Makoswki, a No. 1 draft choice, probably will draw the assignment of containing the Dips' Ray Graydon, who returns to action after missing the last four games because of an assortment of leg injuries.

The Caribours other defenders, Matt Bahr, Phillip Jones, sweeperback Clements and goalkeeper Arnie Mausser, will have their hands full with the dips four-forward offense.

Striker Paul Cannell, (four goals, one assist) Mike Bakic (one goal, two assists) and Bobby Stokes (two goals, three assists), a midfielder who is a "second striker" and Graydon, who replaces Ken Mokgojoa, make up the front line for the 5-1 Dips.

"With Ray in there with Paul, we're a bigger scoring threat," said Bradley. Graydon has a goal and two assists before he was hurt. Despite a 2-0 defeat in Dallas their last outing, the Dips are off to their finest start ever. They have outscored their opponents 11-4 while being outshot 99-96. In scoring their 11 goals. The Dips have been credited with 15 assists. Washington had only 23 assists in netting 31 goals all of 1977.

"Our passing game has improved each game," said midfielder Carmine Marcantonio, who directs the Washington attack. "Once we add a little variety to our short and long-ball style, we'll be even better."

It is Washington's British style of long ball and physical play that could unnerve Clements' youthfull club.

"They're very physical. Maybe it's a little overexuberance because they're winning. I know that's not Gordon's style," said Clements. "He'll straighten that out, though. But soccer is a contact sport and I have no complaints about their style of play."

Clements is the only player-coach in the NASL and insists the double role is more of an advantage than a disadvantage.

"You're right there on the field and when a decision has to be made, you can make it," said Clements. "We do have someone on the sideline who can handle that end of it. But with the young players we have, it helps to be right there with them."

Washington is slowly gaining a reputation as a very physical club. In six games, the Dips have drawn 123 penalties, 32 more than their opponents. The Dips also have been slapped with 13 yellow cards (cautions) and two red cards. Marcantonio, Cannell and defender Mike Dillion have been ejected from games this year.

Dillion drew a one-game suspension for verbally abusing referee J uan Pinto in Dallas. He will be replaced by Alex Pringle tonight.

The defensive unit of Dillion, Pringle, sweeperback Jim Steele, who missed two games with an ankle sprain, Roy Willner, who will draw the assignment of stopping the flashy Sono, Tom O'Hara and goalie Bill Irwin have limited opponents for four goals while posting three shutouts.

Irwin, with 32 saves, is the fourth-leading goalie in the league. Cannell ranks 10th in scoring.