George Allen was asked yesterday who his starting quarterback would be Monday night against the Baltimore Colts and, for a change, the Redskin coach could hardly contain an ear-splitting grin.

"Well," he said, pausing for effect, "we're bringing in Sam Wyche." And when the laughter eased up, the head comedian of Redskin Park offered another tongue-in-cheek zinger. "We'll announce the starting quarter back on Monday," he said, guffawing all the way.

It can safely be assumed the starting quarterback for the Redskin is going to be Joe Theismann. For now at least, the great quarterback controversy apparently is over.

Allen's main concern now is preparing for a 6-1 Colt team that he admitted yesterday "looks dynamite, Ted (Marchibroda, the Colt head coach and a former Allen assistant) has done a heck of a job there," he said.

"We have to play our best game of the year."

The oddmakers obviously agree because they have installed Baltimore as an 11-point favorite, even if the Redskins and won nine of their 11 Monday night appearances, including the last five in a row. How did he account for that record; Allen was asked.

"Lucky," he said.

The Redskins had a lot of that good luck in prevailing over the Eagles Sunday with Theismann at the controls for the first time this season. And Allen knows a good thing when he sees it.

"I think Joe had their defense going for a while there," he said. "He had them on the run. The Eagles have a good defense and if we don't get those penalties . . . we'd probably get 35 or more points. He added a dimension that kept the defense off balance all day."

That dimension - the ability to scramble away from pressure and throw on the trot, will surely be needed against the Colt's aggressive, and now healthy, defense, a unit that intercepted five Steeler pases Sunday and led the AFC in sacks, with 56 in 1976.

Defensive tackle Joe Ehrmann, who has missed Baltimore's last five games with a broken hand, is expected to start against the Redskin.

Allen confirmed yesterday that he made the decision to switch quarterbacks last Tuesday, even though he maintained publicly all during the week he still had not made up his mind.

Last Monday, at the same day after game press conference, Allen had delivered a strong vote of confidence for Billy Kilmer, saying that benching him would imply that Kilmer was the scapgoat for the Redskins' offensive problems. Why did he say that and then bench Kilmer anyway? Allen was asked yesterday.

"It's so hard to explain things and make them come out right," he said. ". . . The decisions I always makes are ones that I think are good for the football team. It's not intended to reflect on anyone."

"Our teeam had been playing poor offensively for one reason or another. It wasn't Kilmer's fault . . . Naturally, I had to do something. The quarterback position, being as potent as it is that's where I had to make a change.

"BIlly work it like a man, like I knew he would. If we had more Billy Kilmers on this team, we wouldn't 4-3. I thought about it Monday night and I talked to Billy and Joe Tuesday morning. There was no intention to mislead anybody.

It was a difficult decision because of the high regard I have for Kilmer. The easy thing would have been not to do it. But I'm always going to do what I did in the past - make the necessary changes. If you don't, you hurt the team, the organization and the fans. The fans really came to life, too. It gave everyone a lift.

"And Billy was on the sidelines, cheering and offering suggestions. That's the kind of guy he is."

Out on the playing field, meanwhile, Theismann was having a ball.

"A friend of mine from high school always goes to the games and he was telling my wife that he thought undersneath the helmet I had to be laughing and having a good time." theismann said yesterday, "Well, i really was."

"Things were just going my way yesterday. I know I was lucky. You know things are going right, though, when you hit a (defensive) guy in teh hands and he drops the ball. We got some breaks, sure, I made sme bad throws, but all you can do is come back the next week and just not do it again.

"I also saw a lot of positive things. On that touchdown pass to Calvin Hill they called back. Len Hauss made a block at the line of scrimmage and threw another one 35-years down the field. On a pass down the sideline to Mike Thomas, all four Philadelphia rushers were knocked down on the ground."

Allen also was full of praise for his offense yesterday and seemed cheered by the prospect of having linebacker Chris Hanburger (torn knee ligament) and wide receiver Charley Taylor (pulled hamstring) available for action against the Colts.

The bad news was that safety Jake Scott (pulled quadricep muscle) and reserve linebacker and special-teams whiz Pete Wysocki (pulled hamstrings) probably will be doubtful for duty in Baltimore, although Allen said Scott may be able to make it back.

Hanburger's return after missing three games leaves Allen with a curious dilemma about what to do with Mike Curtis, the veteran linebacker who would love to start and finish a football against the same team that gave up on him two years ago.

"I'll worry about that when the time comes," Allen said. "Mike is playing real good football. I don't know if Chris will be able to play a whole game. One of the best decisions are made, though, was bringing Mike in to play."

Mike Bragg continues to lead the NFL with 19 punts inside the 20-yeard line and his 36.3 yard net punting average also is tops in the NFL . . . Mark Moseley has kicked 12 field goals, eight of them 40 yards or longer . . . Running back Mike Thomas leads the teams in rushing with 402 yeards in 117 carries . . . Tight end Jean fugett leads the receivers with 19 catches with a 19-yeard-per catch average and three touchdowns.

. . . Allen said once again that he planned to use Calvin Hill more often the rest of the season . . . He said that Karl Lorch forced Eagle quarterback Ron Jaworski out of the pocket on the Eagles' final play of the game, allowing line backer Brad Dusek to bat down his final pass and kill the last Eagle threat. CAPTION: Picture 1, George Allen; Picture 2, Clarence Harmon of the Redskins, right, is stopped by Herman Edwards of the Eagles. Harmon totaled 30 yards Sunday. AP