The Washington Capitals acquired three players and disposed of three farmhands yesterday. On the basis of cold statistics, the maneuvering constituted a loss for the Capitals. But should unfulfilled potential be realized, Washington General Manager David Poile could emerge a winner somewhere down the line.

In a bid for immediate help, Poile dealt center Jim McGeough to Pittsburgh for forward Mark Taylor. He also signed ex-Ranger center Mikko Leinonen for delivery at the conclusion of the Finnish playoffs later this month. In a deal in futures, Poile traded center Dean Evason and goaltender Peter Sidorkiewicz to Hartford for forward David Jensen.

Taylor and McGeough will report to their new clubs today. Evason, Sidorkiewicz and Jensen will stay in Binghamton, the farm team shared jointly by the Capitals and Whalers, although Jensen will practice with Washington today and Thursday.

Taylor, 27, who has watched Pittsburgh's last six games from the press box, collected only seven goals and 10 assists in 47 games for the Penguins. But he was college hockey player of the year at North Dakota in 1980 and had 24 goals last season after being traded to Pittsburgh by Philadelphia.

Jensen, 19, has produced even less this season -- four assists in 13 games with Hartford, five goals and eight assists in 35 contests at Binghamton. But Jensen, a 1984 Olympian, was a first-round draft pick in 1983; none of the other players involved in yesterday's transactions was chosen earlier than round five.

Leinonen, 29, stayed home this winter after splitting last season between the Rangers, where he recorded three goals and 23 assists in 28 games, and Tulsa of the Central League, where he had 15 goals and 23 assists in 33 games.

Sidorkiewicz, 21, has posted a 23-8-4 record with a goals-against mark of 3.04 for first-place Binghamton. McGeough, 21, collected 32 goals and 21 assists in 57 games, while Evason, 20, had 20 goals and 41 assists in 56. Evason, returned to Binghamton by the Capitals on Monday, managed three goals and four assists in 15 games here.

The deals came as a surprise, since Poile had said Monday that he did not expect anything to happen before the NHL trading deadline at noon yesterday. But he called Pittsburgh to check on Taylor's status and wound up making a better offer than Edmonton and the New York Islanders, who also expressed interest.

Poile had been after Jensen for some time without success, so he was receptive when Hartford General Manager Emile Francis called and said Jensen was available. No doubt, Francis was influenced by Jensen's harsh criticism of the Whalers in a recent newspaper article.

"For a guy who's not doing anything, I sure got involved in a lot of things," Poile said. "It's been an unbelievable morning. Everything came out of left field.

"Mark Taylor was one of the best collegians ever and a real contributor in Philadelphia on a good hockey club. Obviously, something happened this year, because from day one he was not what he was last year.

"But I know Mark Taylor a little bit and he's a good team player. I think he can help us. Jim McGeough can play in the NHL, but he's too undisciplined for our type of play.

"As for David Jensen, we'll have to wait three or four years to see who gets the better of the deal. You're gambling when you make this kind of trade.

"I happen to think in the long run David Jensen will prove out to be the best of the three players. He was a first-round pick and he's only 19. He's had a disastrous start to his pro career, but I'm sure there are two sides to every story.

"The name of the game in the '80s in hockey is skating and David Jensen is one of the best skaters in hockey. He has a lot of maturing to do to understand the game, but we're prepared to work with him."

Poile said that he expected Evason to play for Hartford next season but felt lack of size and speed would limit his development. As for Sidorkiewicz, Poile said that he had been a "real success story" and could swing the trade in Hartford's favor but the Capitals already have three solid goalies and a fourth progressing well in Alain Raymond at Three Rivers.

Leinonen was signed for the rest of this season and the playoffs, for possible penalty-killing help or in the event of injuries.

Taylor, a onetime teammate of Dave Christian at North Dakota, was delighted by the news.

"This is a new chance and a fresh start," Taylor said. "It's been a frustrating year for me, playing a few games and then sitting out for a while.

"(Pittsburgh Coach Bob) Berry just didn't like something about me and I got off on the wrong foot right from the start of the season. Washington has a great team and a solid organization and I hope I can contribute."

Evason was collecting his gear at Mount Vernon when he was summoned to the telephone.

"David called and I thought, 'Oh, good, he made a trade and I'll be able to stay here,' " Evason said later. "This is a shock. I was up and down and I never really got a fair shot, but I think Washington is a first-class organization and I'm sorry to leave it."

Poile's phone call also surprised Sidorkiewicz, who said, "I have mixed emotions. One minute I feel happy, the next minute I feel down. Hopefully, in the long run it'll be the best thing. Maybe I'll be able to get a better shot and quicker."