CARLISLE, PA., JULY 22 -- NFL owners will meet Thursday in Chicago to establish roster sizes for the 1990 season and it appears the six-man developmental squad that coaches enjoyed so much will be terminated.

Developmental players -- those who are cut from the team, then clear waivers and can't catch on with another team -- earn $1,000 per week, instead of the $50,000 minimum salary, and the NFL Players Association challenged the concept in court.

Now instead of a 45-man active squad, a two-man inactive squad and a six-man developmental squad, the NFL is considering a straight 47-man roster.

Redskins Coach Joe Gibbs and General Manager Charley Casserly bitterly criticized the possibility of that kind of change.

"I think that would be a disaster," Gibbs said. "People say we didn't have that 25 years ago. But 25 years ago you didn't play 16 games, have a longer playoffs and use all these multiple formation sets. Making a change like this would just mean you couldn't practice. You'd be asking wide receivers and offensive linemen to go full bore on Sunday, then come back on Wednesday and simulate your next opponent's plays. That's just asking too much.

"Could we do it? Of course we could do it. But it wouldn't be the same quality. We could have walk-throughs during the week and play on Sunday. But it wouldn't be as good. We could draw the plays up in the dirt, but it wouldn't be the same. I'll tell you, I'm proud of the Redskins. We've always voted for more numbers and to do what it takes to make the game better and more competitive."

Casserly said: "I'd like to hear the reasoning. Our feeling is that we'd like to be able to keep young players and develop them."Fresh and Unfinished

One of the most watched rookies in camp will be quarterback Cary Conklin, a fourth-round draft pick from Washington. He had an odd college career, being forced into action in the seventh game of his sophomore season (his scheduled redshirt year), then suffering through a constant change in offensive philosophy.

For that reason, the Redskins believe he's an unfinished product, and at 6 feet 4, 215 pounds, they compare him favorably to starter Mark Rypien and backup Stan Humphries.

"I want to come in and show them I can play football at this level," Conklin said. "I've learned a lot watching films this summer and this is going to be another learning experience here. We ran some of the same things my last year in college, but there's a lot more to it here."The Unsigned Six

With center Jeff Bostic, linebacker Greg Manusky and tight end Don Warren agreeing to terms and running back Reggie Dupard and kick returner Joe Howard signing contracts, six veterans remain unsigned: running back Gerald Riggs, tackle Darryl Grant, safety Todd Bowles, and linebackers Markus Koch, Ravin Caldwell and Monte Coleman. . . .

Players will be on the field for two practices on Monday, at 9 a.m. and 4 p.m. They'll work once on Tuesday, then scrimmage the Pittsburgh Steelers in Latrobe, Pa., on Wednesday.

REDSKINS IN 2ND DECADE IN NFL

Player............Pos......Yr......Acquired*

Monte Coleman.....LB.....12.....D-1979

Jeff Rutledge.....QB.....12.....FA-1990

Don Warren........TE.....12.....D-1979

Jeff Bostic.......C.....11.....FA-1980

Art Monk..........WR.....11.....D-1980

Darryl Grant......DT.....10.....D-1981

Russ Grimm........G.....10.....D-1981

Joe Jacoby........T.....10.....FA-1981

Mark May.........G-T.....10.....D-1981

Mike Tice........TE.....10.....FA-1989

James Wilder.....RB.....10.....FA-1990

*How and when player was acquired.

D-drafted, FA-Free agent.