The youngsters, rookies yet, learned this early on about the Washington Redskins' training camp: a scrimmage can be like a game and a practice like a scrimmage. The food at Dickinson College is so good you can eat yourself right out of the NFL. And just because you're asleep at night doesn't mean everybody else is.

Cornerback Barry Wilburn, an eighth-round draft choice from Mississippi who has earned the highest praise from Coach Joe Gibbs and Richie Petitbon, coach of the defensive secondary, discovered this morning during warm-up drills that Anthony Washington was missing. So did Raphel Cherry, a fifth-round selection who played quarterback at Hawaii but now is working out at free safety, a position he has adopted with considerable success.

Not that Wilburn and Cherry were presumptuous enough to ask, but both men wondered what had become of the five-year veteran acquired by the Redskins in 1983 to help bolster a flagging defensive backfield.

"I kept looking around at practice," Cherry said this morning, "looking and wondering where Anthony was. Then it came to me."

"I couldn't find him either," Wilburn said. "But it's that time of year. You learn somebody can go any day. Even if that somebody's you."

Thursday night, Redskins General Manager Bobby Beathard traded cornerback Washington to Tampa Bay for third-year offensive tackle Kelly Thomas. Gibbs said the reason for trading Washington was that "We were convinced that he wasn't going to make it," Gibbs said this morning, "not with the addition of Tory Nixon," the team's No. 1 draft choice who signed a four-year contract Thursday.

"We all sat down and made a commitment to look at that thing," Gibbs said. "We had several young guys who looked real good to us. I told Bobby to look for a place that needed a defensive back and to find someone who could help out our situation."

Gibbs said the trade also was made after evaluating the team's performance in the preseason over the last four years. "I think we started way too slow," he said. "I just want to start out faster now and I'd like to see us play better early. All I'm doing is trying to speed things up."

Petitbon said Wilburn's outstanding role in the scrimmage against New England last Saturday convinced the coaching staff he had a solid future with the club. Wilburn, who is 6 feet 3 and 186 pounds and already has won a reputation as a terrific open-field hitter, had played both cornerback and free safety at Mississippi.

"When we saw him at camp," Petitbon said, "we saw that he had this great size and was running the 40 (yard dash) in 4.5 and some change. We tried him at corner and it's been working out fine for us. To get a good corner in a late round who can help you, there's a heck of a lot of luck in that."

Petitbon has shied away from thrusting rookies into the starting lineup no matter how impressive one may perform in camp. But doing so now would not be unprecedented. Cornerback Darrell Green emerged as a star in his first regular-season game in 1983, after chasing down Tony Dorsett of the Cowboys and saving a sure touchdown. Some say Wilburn may develop into a player of Green's caliber.

"It's not that you don't like rookies," Petitbon said, "it's just that they have so much to learn and it's not fair to play them until they're ready. It's kind of like rushing a boxer early in his career. He gets in there and gets knocked out and he's never the same again."

Wilburn has his reservations about being pushed too quickly. "I'd like to be quicker on the reads," he said, "but that will come with experience. The older guys react quicker. I want to get to the point where I don't have to think about where to go and simply move to it instinctively. Then I'll be a much better player."

It is apparent that Cherry also has gained enormous respect from the players and the coaching staff. Petitbon said the Redskins "have some legitimate talent back there, the most we've had in a long time," and one veteran defensive player commented on the intensity of the competition that has swept through camp.

Wilburn said, "The coaches don't sit you down and tell you when you did something right. It's a day-to-day thing. You can't rest on old laurels or think about what you did just yesterday. You have to do the job and please them every day or else you won't survive to make the roster."

Cherry, who has shown a talent for making quick secondary adjustment calls under fire, said several NFL teams scouted him as a quarterback and that he "wanted to play there if it weren't for long-range goals. I knew being in Washington, there was the opportunity to play other positions. It all comes down to wanting to adjust to my new position. If you really want to and put your mind to it, you can. At least that's what I was taught to believe."