Heinz Wirtz, a defender, has been signed to a three-year contract with the Washington Diplomats during Coach Ken Furphy's three-day trip to West Germany.

Furphy, who returned to Washington yesterday a day earlier than expected, also made an offer to a winger, whom he declined to identify, from a West German Division II club. General Manager Duncan Hill said he is waiting for a response from the winger, which "could come in a few days."

The Dips are 3-1 and second in the NASL's Eastern Division despite having scored just six goals. Furphy expects Wirtz, who can play all four back positions and may see some time at midfield, to help the team's offense as well as the defense.

"He is an attacking defender," Furphy said. "A defender has to take risks before he can go forward. So many are afraid to take those risks."

Wirtz, 26, has played more than 80 games for Fortuna Dusseldorf, a Division I team in the Bundesliga, West Germany's top professional league. dHe played for Fortuna in European Cup matches this year before the team was eliminated.

The Dips turned their attention to West Germany two weeks ago when a European agent contacted them to say the two players were available. Wirtz was flown here 10 days ago for a look. "Ken saw him for 45 minutes and said, 'Let's sign him,' " said Hill.

For the past eight weeks, the Dips have sought two players from Argentina, but have been frustrated by the negotiations.

"We offered $150,000 (for one of the players), which is quite a sum of money for a club like ours," Hill said. "But as soon as he finds out it's an American club, the price goes up to $225,000, and so forth." Hill said the team will pursue the negotiations, although his enthusiasm has dimmed on the pair, whom he also declined to name.

The addition of Wirtz increases the Dips' roster to 18. Nine more spots are available.

Wirtz is expected to arrive here today. Furphy said he will determine Wirtz' availability for Sunday's game in Toronto by "how tired he is and how quickly it appears he can adapt to artificial turf."