Maryland, Georgetown and Howard must replace graduated centers. George Washington has a center but has lost three top players. American has Bob Bowers and four other regulars back. Catholic has the experience it lacked a year ago, but lost it top recruit to Georgetown. George Mason may have its best team ever but the schedule may prevent it from improving last season's record. And Navy must replace its alltime leading scorer.

Tomorrow, with the leaves still on the trees but one snowfall already melted, college basketball teams throughout the area and around the country begin answering the questions their fans have been asking all summer. They will have six weeks to choose their best players.

And with the NCAA Tournament having expanded to 48 teams and the National Invitation Tournament having gone to 32 teams, the only local team with no chance to get into one of those two postseason event is the Bullets.

Here is a look at the local teams:

AMERICAN UNIVERSITY: Gary Williams comes off a 14-13 rookie season as coach of the Eagles with one player with superstar potential, 6-foot-4 swingman Bowers.

Bowers averaged 22.2 points a game a year ago, becoming the second-leading sophomore scorer in the nation; he will probably be asked for even more this season.

Williams also has 6-foot-7 center Bob Harvey, 6-2 guard Chris Dye and 6-5 Leon Kearney, and their experience should help considerably.

CATHOLIC UNIVERSITY -- The 1978-79 season was not a pleasant one for coach Jack Kvancz as the Cardinals, coming off their best record in his regime the previous year, 13-13, fell to 6-20.

There is experience this season in Tom Lamb, the leading returning scorer, a 6-2 guard who averaged 17 points a game; 6-3 John Rogers; 6-8 Mike Neville; 6-6 Bill Dooley; 6-2 Joe Colletta and point guard Donnie Farrell.

HOWARD -- If Coach A. B. Williamson can find a suitable replacement for graduated center Dorian Dent, the Bison could have their best team ever. f

Coming off a 16-12 season capped by a second-place finish in the MEAC Tournament, Howard adds two key tranfers to its starting lineup: former All-Met forward James Ratiff, 6-8 and 5-10 jitterbugging guard Rodney Wright, both of whom sat out last season after transferring.

Larry Spriggs, a 6-7 junior, averaged 15.5 points and 9.7 rebounds a year ago, but the key for Williamson may be the play of 6-11 sophomore center James Terry, who played little last year behind Dent. The top freshman is 6-5 wing guard Bernard Perry.

GEORGE MASON -- The Patriots turned in an impressive 17-9 mark a year ago in their first season of Division I basketball. With leading scorer and rebounder Andre Gaddy and John Skaff back, it would seem logical that GMU would improve on that mark.

But patroit Coach John Linn has upgraded the schedule to include games with Richmond, Bowling Green, Virginia Military and Stetson, all on the road, and that will make it tougher.

But with Gaddy, a 6-9 junior who averaged 20.3 points and 9.9 rebounds, and Skaff, who averaged 14.6 points, the Patroits will be competitive.

GEORGETOWN -- The Hoyas are coming off their best season in history, 25-4, and if Ed Spriggs can fill the large (literally) shoes of center Tom Scates, they may do even better this year.

Back for their senior season are the Dynamic Duo of 6-7 Craig (Sky) Shelton and John (Bebe) Duren, who played on the United States Gold Medal Pan American team this summer.

Both were dynamite a year ago, but the key added ingredient for GU last season was the added outside scoring punch of 6-2 Eric (Sleepy) Floyd, who should be even better as a sophomore.

The 6-9 Spriggs a 23-year old sophomore, saw a fair amount of playing time for the sometimes foul-prone, sometimes injuried Scates last year and showed potential. If he develops, and if 6-5 freshman David Blue (who decided to go to Georgetown over Catholic at the last minute) or backups like Jeff Bullis, Eric Smith, or Al Dutch (back in school after a year's absence) can replace the super-steady Steve Martin at the small forward spot, Georgetown should be back in the NCAA Tournament with ease.

GEORGE WASHINGTON -- Coach Bob Tallent has his bulwark, 6-10 center Tom Zagardo, back and he will lean even more heavily on the senior center now that Bob Lindsay, Mike Samson and Tom Tate have graduated.

Zagardo led the Colonials through their first losing season (13-14) in five last year, in scoring (16.0) and rebounding (8.9) a year ago.

Also back are former Maryland guard Brian Magid (12.3), 6-7 forward Tom Glenn, and 6-0 junior Curtis Jeffries. Tallent is hoping Magid can be more consistent with his long-range bombs this season.

MARYLAND -- Four starters are back but center Larry Gibson is gone, and most people are picking Lefty Driesell's team for a fourth straight season in the middle of the ACC pack.

Driesell would like to see 6-10 sophomore Taylor Baldwin develop into his starting center so he can keep last year's ACC rookie of the year, 6-8 Buck Williams, twinned with Albert King at forward.

He would also like to move 6-7 Ernest Graham, who can shoot either the lights or his team out on the same night depending on whether he is hot or not, to forward, his natural position. That would leave Dutch Morely, Greg Manning and Reggie Jackson to share most of the time at guard, and would allow Driesell to bring Graham off the bench for offensive punch and senior John Bliney in up front for defensive help.

NAVY -- Kevin Sinnett, the Academy's alltime leading scorer, has graduated, leaving Coach Bob Hamilton with a gigantic hole to fill at forward. Hamilton does have back Chuck Greene, who averaged 13.5 points a game last season; 6-1 junior Kevin Catherman; 6-1 senior Bruce Grooms; 6-3 swingman John Greshau; and senior center Brian Burlingame.

VIRGINIA -- This is a budding superteam about to flower. Coach Terry Holland has back Jeff Lamp, the ACC's leading scorer a year ago, Lee Raker, Mike Owens and jeff Jones. But the coup de grace is 7-3 freshman Ralph Sampson, perhaps the most highly sought high school player since Lew Alcindor. The Cavaliers were 19-10 a year ago and reached the second round of the NIT.

SMALL COLLEGES -- Bowie State, the University of District of Columbia, Southeastern, and Prince George's Community College all have basketball programs, but it is difficult to gauge the strenght of small college teams until practice begins, because you're not sure who will report.

PGCC, 18-8 a year ago, does return leading scorer James MeNeil; Southeastern has Dexter Ravenell and Jesse Harrison back; former Maryland assistant Wil Jones, who has taken over as coach at UDC, will depend heavily on Barry Frazier, a 26-point scorer a year ago.