For the past 10 days, Joe Gibbs and his staff have worked patiently with 50-plus potential Redskins, trying to determine how many have a future in pro football.

Saturday, when these players meet the Colt rookies in a 2 p.m. controlled scrimmage at Goucher College in Towson, Md., the coaxing and handholding ends.

With training camp one-third over and the bulk of the veterans preparing to begin practice Sunday, Gibbs is facing the first hard decisions of his head-coaching career. He is eager to see how some of the young Redskins do on their own, without a coach nearby to correct them or remind them of their assignments.

Two days ago, in an intrasquad scrimmage, there were scads of missed assignments, botched plays and unimpressive performances. Gibbs has spent ensuing practices trying to smooth out the rough spots.

"We'd like to hook professional," he said.

He'd also like to get a clearer picture about a number of players and positions that are vital to the teamhs plans:

At running back, 12 Redskins are vying for a maximum of six roster spots.Four of those backs will play in the scrimmage: holdover fullback Rickey Claitt, 1980 draft pick Lewis Walker, former Buc George Ragsdale and former Giant Otis Wonsley.

Claitt, who played so well early last season before being benched because of his inability to pick up blitzing linebackers, is called by Gibbs, "My biggest surprise so far in camp."

Gibbs said Claitt wasn't outstanding in earlier minicamps, but has made a far different impression here.

"He already has flattened three linebackers, hitting them head-on in the chest," Gibbs said. "You didn't see that more than once a camp, usually, and he's done it three times in one week. He just hs that quick burst. It really catches your eye. And he's not afraid to hit people, either."

Wonsley and Ragsdale both started strongly, but they'll need good performances Saturday, as will Walker, to stay around. Gibbs said he'd like to reduce the number of backs to 10 or fewer as quickly as possible, and he doesn't want to drop any incoming veterans until they've had a chance to practice.

Other than Art Monk, who won't play in the scrimmage, Gibbs says his wide receivers are "all bunched in one lump with no one sticking out at you. I'd like to see some people break away."

Injuries are hurting the evaluation process. Zion McKinley, who made the team last year as a free agent, has leg problems and will be held out. Virgil Seay, another pleasant surprise to the coaches, suffered a slight pull in practice today and may not be able to play.

Seay, a 5-foot-7, 170-pound free agent who was cut by Denver last year, probably is the fastest receiver in camp. Despite his size, he has had a number of outstanding practices that have made him a legitimate contender, along with rookie Charlie Brown, for a roster spot.

Charlie and Virgil are different types of receivers in a lot of ways," Gibbs said. "Virgil is the real speed guy.He can come off the ball quicker than anyone in camp and he can go deep. Charlie is more of a glider, a guy who slips into holes. Both of them have had good camps so far."

With another veteran, Ken Harrison, plagued by injuries, Gibbs is bringing to the scrimmage John McDaniel, who has started on and off the last two seasons. McDaniel probably will have to play well to improve his chances of staying.

Gibbs will keep either three receivers and three tight ends or four receivers and two tight ends. Which way he goes will depend greatly on the play of Rick Walker, a tight end who also can move outside. Walker, who will be used at both spots in the scrimmage, has to prove to the staff he is serious about his work. If they decide, he isn't, some of Gibbs' offensive flexibility will be diminished and he would have to go with four receivers.

The Redskins will carry three quarterbacks, but only one spot is left since Joe Theismann and Tom Flick won't be cut. Flick and another rookie, Phil Kessek, will play in the scrimmage. Kessel, an 11th-round choice from Northern Michigan, is contending with veteran Mike Kirkland for the No. 3 position. He has lagged at camp, but could benefit from a good showing Saturday.

Kirkland will be on hand; but only as a punter. This will be the first round in what should be a camp-long duel between him and holdover Mike Connell for the punting chores. Again, roster maneuvering could be a factor in the outcome. If Kirkland earns a spot as both punter and third quarterback, it would free a place on the roster.

The first weeks of camp haven't done much to clear up the backup linebacking problem. Dave Graf, who played six years with the Browns, is making a decent transition from the outside to the inside but certainly isn't a lock to play behind Neal Olkewicz. Farley Bell, a 1980 fifth-round choice who left camp last year, is being pushed by rookies Herb Spencer and Mel Kaufmann and free-agent Quentin Lowry for an outside shot.

Three-fifths of the Redskins' probable starting offensive line against Dallas will be employed in the scrimmage. Guard Melvin Jones had an outstanding showing Wednesday night and he'll be watched closely along with tackle Jerry Scanlan and guard Fred Dean. No. 1 draft choice Mark May also will play.

"I really don't know what to expect," Gibbs said of the scrimmage, in which each team will run 15 plays before turning over possession. "It's time for the coaches to get out of the way and see what they can do on their own. Then a lot of the cuts will be determined almost on their own."