While George Allen was still tinkering with his defense yesterday, Billy Kilmer was aying he is not concerned about struggling Redskin offense heading into tonight's final exhibition game of the season - an 8 p.m. encounter with the New York Jets at RFK Stadium.

"We have no problem except a lack of concentration," said Kilmer, who will play at leasdt a half, and maybe longer. "We've been stopping ourselves with penalties. We should have four or five more touchdowns. That's what we have to eliminate - mistakes - and we have to get consistent."

Allen, meanwhile, eliminated another player yesterday to make room for defensive end Duncan McColl, the team's top choice in the 1977 draft. Placed on waivers Tuesday, McColl was reactivated yesterday, it has been learned, and will be available to play against the Jets.

Third-string quarterback Brian Dowling was cut to make room on the roster for McColl. Dowling, a fourth-year pro, played college ball at Yale before joining the Canadian League. He was in his first season with the Redskins.

Allen indicated he also will not play running back Mike Thomas or cornerback Pat Fischer against the Jets, preferring to give them another week to recover from ailments that have idled them most of the summer.

Thomas took his sore left hamstring to a Chevy Chase neurology clinic Wednesday to determine if his muscle problems were a result of nerve damage in some other part of his body. A series of tests indicated that was not the case, and the injury is still being diagnosed and treated as a pulled hamstring.

Thomas' agent, Guy Draper, said the Redskins also had consulted a Baltimore physician who specializes in muscle problems. Trainer Bubba Tyer said Allen had spoken with the doctor, a personal friend, but that Thomas remained under the care of team physician Stanford Lavine.

Thomas had two workouts yesterday at Redskin Park, mostly joggling and riding a stationary bicycle. The Redskins hope he will be able to rejoin regular drills by the middle of next week and be able to play in the season opener Sept. 18 against the New York Giants. Tyer said Thomas was making "excellent progress" and should be ready by opening day.

With Thomas, Fischer and Chris Hanburger not available tonight an anticipated crowd of 37,000 will have to be content with seeing most of the other Redskin veterans play all the way against a Jet team that is 3.3 in preseason, including victories in their last two games.

It will be Sonny Jurgensen Night at RFK Stadium, with the former Redskin quarterback being honored at halftime. The Washington Post is sponsoring the game, and $2 from each ticket sold after the first 14,000 will go to the new Washington Post Charitable Trust.

Kilmer, meanwhile, said he was looking forward to more work. He has not played longer than 1 1/2 quarters in the Redskins' previous five exhibitions, "but it's time t get ready for the opener," he said.

"I'm ready to play, Physically, my (left) knee is just going to be something I have to live with. But my arm is fine, I've had no problems with it since the start of training camp."

Kilmer, hitting 71 per cent of his passes so far, hopes to put a little added life into a Redskin offense that has managed only seven touchdowns in the preseason, six through the air.

"This is going to be a good test for us," Kilmer insisted. "They've (the Jets) got youth and enthusiasm and they'll be flying high after winning two in a row. They're probably starting to believe in themselves.

"It'll be a good game to get ready for the Giants, too. Both teams play similar kinds of defense. They both use a lot of zones, things like that. So we should have a pretty good idea of where we stand."

The Redskins, now 3-2 in preseason, surely have noticed they are being outscored, 41-3, by the opposition in the first quarter, putting the defense in the hole almost every week.

Last week the Patriots scored 21 points inthe opening quarter, though Kilmer insisted. "I won't base anything off that last game. It just happened. It's over, and I don't think we have any problems we can't correct."

The coaching staff would like to see more improvement in a pass rush that put little or no pressure on Patriot quarterbacks last week, and a decrease in turnovers.

The Redskins have lost eight fumbles, had six passes intercepted and been penalized 46 times for 477 yards in preseason. Allen keeps saying that cannot continue, but many of his players apparently aren't listening.

The Jets come into RFK Stadium with offensive problems of their own. They have scored only six touchdowns in preseason and are averaging but 256 yards offense per game.

New head coach Walt Michaels probably will field the youngest team in the NFL this season in still another rebuilding year.

Richard Todd will open at quarterback and go most of the way. He has connected on 43 per cent of his passes, but the Jets are trying to become a ball-control, running team.

Todd will hand off tonight to a cast of thousands. The Jets alternate eight running backs, and Todd can run himself as his five-yard per carry average attests.