The Washington Diplomats look to extend their indoor soccer winning string to three games tonight when they host the Tampa Bay Rowdies at the D.C. Armory at 8.

The same teams will tangle again Sunday at 3.

Washington began its first indoor season on a successful note two weeks ago by whipping the Fort Lauderdale Strikers twice within 18 hours. The Dips won the first game, 9-2, and the second, 8-5.

The indoor version of soccer appears to be a hit with spectators. Played much like ice hockey, the game is much faster than the outdoor game, with frequent body contact and more goals.

Dips midfielder Art Welch, the North American Soccer League's No. 11 career scorer with 113 points scored 12 points (five goals and two assists) in the two games. Gary Darrell, the only remaining member of the original Diplomat team that was formed four years ago, has scored eight points, one more than Randy Garber.

Washington coach Gordon Bradley has been in England recruiting and may not be back for the two games. If not, defender Jim Steele will fill in as coach.

The Rowdies, who won the NASL indoor soccer championship two years ago (no series was played in '77), will be playing their first indoor game this season. Gordon Jago, a former English coach, will make his debut as the Rowdies' head coach.

Tickets are on sale at area Ticketron outlets, Pentagon Ticket Service, the Leather Ball in Gaithersburg and the Dips' ticket office at RFK stadium.