The Washington Diplomats will announce the signing of Wim Jansen, a member of Holland's World Cup team in 1974 and 1978, at a press conference Thursday according to informed sources.

Jansen, 33, has been a member of the Feyenoord team in Holland for 15 years. He played with new Dip Johan Cruyff on the Dutch national team for several years and on the World Cup team of 1974 which advanced to the final game before losing to West Germany.

Jansen is a defensive midfielder who probably will occupy a sweeper position with the Diplomats. He is the defensive player the Dips have been looking for to team with Cruyff and Juan-Jose Lozano, both offensive-minded players who have been signed in the last month.

Ironically, Washington Coach Gordon Bradley began negotiating with Feyenoord to purchase Jansen long before Washington became involved in the deal that brought Cruyff here last week.

Like Cruyff, Jansen will sign a one-year contract with options to renew for two more. He will be paid about $150,000 a year. His purchase price is believed to be about $500,000.

Jansen has been one of Europe's top midfielders for the past 10 years. He was considered a perfect foil for Cruyff on the national team -- when Cruyff went forward to set up the offense, Jansen stayed back to plug the gap. That undoubtedly will be his role in Washington.

The signing will be the third in three weeks for the Dips, all of them big money transactions, although the Cruyff deal overshadows the others.

With the team already in Jacksonville training, the Dips may make one more acquisition, at most. Jansen's purchase should round out the starting lineup.