CARLISLE, PA., JULY 30 -- The Washington Redskins may have thought it a waste of time this summer when a couple of their top personnel people, including General Manager Charley Casserly, made scouting trips to the Patriot Center for a glimpse of the Washington Commandos of the Arena Football League in action.

Today, the Redskins responded to a shortage of wide receivers by signing Commando Chris Armstrong to a contract that will at least get him a training-camp look.

To make room for him, wide receiver Charles Lockett (strained quadriceps) was placed on injured reserve/waivers. Lockett may be claimed by any other team, but if he clears waivers, he'll return to the Redskins payroll and be on injured reserve the rest of the season.

So Armstrong, who played at Fayetteville (S.C.) State, enters training camp with only a slim hope of making the team. He's here because the healthy wide receivers were running too many routes. Now while running routes, he hopes he'll be noticed.

"You have to look around and see this team has a lot of experienced wide receivers," he said, "but I'm getting a chance to come in and show what I can do. All you can ask is a chance."

The Redskins originally told him to report on Wednesday, but when Lockett got hurt in a scrimmage last week, Armstrong received a phone call Saturday and was told to come quickly (he missed the Commandos final game and was back home in South Carolina).

"I thought I'd be coming up for a tryout and to get signed is a bonus," he said. "I'm real excited about the possibility of having these guys watch me."Green Gets Stitches

Cornerback Darrell Green had been on the practice field about eight minutes when he began as one of the first casualties of training camp. A pass caught him flush in the palm of his right hand and opened a nasty cut in the webbing between the middle fingers.

The cut required five stitches to close, but Green was back on the field this afternoon with the fingers taped together and a glove protecting the hand. . . . Meanwhile running back Kelvin Bryant, returned to practice. He took part in only two days of work last week before straining a hamstring.Four Down

When four veterans signed contracts this morning, the Redskins cut four free agents to stay at the 80-man roster limit: guard Jay Fagan, defensive back Larry Vladic, running back George Searcy and linebacker Kevin Wolfolk.