Maryland and Georgetown will play for the unofficial area college basketball championship tonight at 9 p.m. in the D.C. Armory. The Terrapins will be without a key player and the Hoyas are uncertain about the availability of one of their stars.

In the 7 p.m. opener, American and Navy, both 1-0, will play in this, the third and probably last Tip-Off Doubleheader.

Maryland (2-0) will be without starting center Buck Williams, who broke the ring finger on his right hand in practice last week. He is out for at least two more weeks.

Georgetown (1-0) may be without 6-foot-7 forward Craig (Big Sky) Shelton, who underwent minor oral surgery last week and is still in pain. If Shelton does not start, Jeff Bullis will be the starting forward. Shelton practiced yesterday and is expected to play.

American, which dropped two games to Navy last season, is led by 6-4 Russell (Boo) Bowers, who opened his junior year with a 33-point performance against Towson State, a game the Eagles won by three points.Navy Coach Bob Hamilton is rebuilding, Kevin Sinnett having graduated.

The Georgetown-Maryland game, while too early in the season to be a definitive test of the strengths of the teams, has produced close games the last two years, Maryland winning in 1977 and Georgetown a year ago.

With Williams out, the Terrapins will lean heavily on junior forward Albert King, who scored 28 points to pull the Terps past a weak Penn State team, 56-55, Monday night. Georgetown, 25-4 last season, has yet to be tested, opening with a 98-47 win over Bowie State.

With Taylor Baldwin and David Henderson sharing the center spot for Maryland, the Hoyas will undoubtedly try to use their extra quickness to run on the Terps. Shelton and Ed Spriggs are crucial to that running game because they must get the ball off the boards against the bigger, slower Terrapins.

Georgetown is ranked 17th in this week's AP poll. Maryland is unranked.

The doubleheader was originally scheduled for Capital Centre but a mixup put the Bullets and Knicks there tonight.

Ticket sales for the doubleheader have been slow and Maryland Athletic Director Carl James has already indicated that Maryland will probably pull out next season.