The Washington Diplomat did not practice yesterday after having lots, 3-2, Sunday to the Tulsa Roughnecks. Instead, they listened. And listened.

For 90 minutes Coach Ken Furphy talked to his players. He talked about basics, about not making silly mistakes, about making the effort necessary to improve.

"There are certain things you learn over the years that you absolutely cannot do and win soccer mathces," Furphy said. "We did some of those things Sunday because players weren't thinking. If they do the things they have to, work to keep improving, we'll get better and be good. But this team has to do the extra work."

Furphy talked to the players as a group, then to individuals. He pointed out to captain Peter Baralic, who was yanked 30 minutes into Sunday's game, that he "disappeared" when the Dips fell behind, 2-0.

He told Ole Mikkelsen he was surprised the rookie forward had not been working out on his own to strengthen his left foot since Mikkelsen is strictly a right-footed player.

He let defender Peter Carr know he had made some basic mistakes that had hurt the team in crucial situations. He made it clear to defends Benny Dargle that he was not pleased with his ball distribution or the way he had been working in recent weeks.

The Dips are 8-4 and, with road games in Minnesota, Jacksonville and Chicago next on the schedule, Furphy knows his team cannot afford a letdown if it is to remain near the top of the league and within striking distance of the suddenly vulnerable slumping Cosmos.

Furphy and General Manager Duncan Hill met yesterday to discuss possible acquisitions before the June 16 deadline for signing foreign players and the July deadline for trades within the NASL.

Furphy would like very much to have another player who creates his own chances. He used Trevor Francis, who was with the club in Detroit two years ago, as an example of that kind of player.

But getting Francis would require paying a huge transfer fee and a huge salary, which the Dips cannot afford. "It would probably take in the neighborhood of $2 million to get a Trevor Francis," Hill said. Right now that just isn't realistic for us."

So Hill and Fuprhy will continue to search the league for a player who might not be Francis but who would make the Diplomats more consistent up front.

"We're looking to get that additional player that will give Ken the kind of balance he'd like to have," Hill said. "But we're not in a position where we have to make a panic move. We want to take our time and make a move that will help us not just now, but in the future."

Paul Cannell, benched by Furphy for not producing, will begin a weekly spot on WDVM-TV-9 this Friday on the 6 p.m. news. "Paul has more than made up for what he hasn't done on the field with he's been able to accomplish for us publicitywise," Furphy said, adding that he has no intention of trading Cannell . . . The Dips do not play at home again until June 17, when the Cosmos return . . . Furphy and Hill expect Furphy to draw a fine, his second this year, for criticizing referee Gino D'Lppolito Sunday. Furphy was fine $200 after the first Cosmos game for a postgame exchange with referee Paul Avis. CAPTION:

Picture, Benny Dargle of Dips dribbles around Tulsa defender Dean Neal in 3-2 loss. AP