KEN HOUSTON is almost 35, the age at which most pro football players, other than quarterbacks and defensive linemen, start thinking about life after Pete Rozelle.

Houston's position -- strong safety -- demands the strength and endurance of a young man. He must neutralize the advances of increasingly more agile tight ends who look like Charles Atlas and run like Bob Hayes. Houston is only 6-feet-3 and 198 pounds.

There has been no sign of a Houston letdown. His string of 11 straight Pro Bowl appearnaces probably will be extended to 12 in this, his 13th season, barring crippling injuries.

But his quest for excellence has taken its toll on Houston. His body is still remarkably young, his waist line firm, his muscles supple and lean. But he acknowledges there is a different Ken Houston whirling around inside that body.

"I can see the end coming," he said. "When? I don't know. But I'll sit down at the end of this season and talk it over with everyone. I want to go out on top; I don't want that knock on my door telling me I was cut. Yes, this could well be my last year, but I'm not sure.

"I'm out this year to be the best safety in pro football. I really think I can be better than I have been the last three or four years. I feel great and I haven't lost my desire to play.

"But it gets harder. You know you are getting old when they blow the whistle and the young guys can start practicing right away and it takes you five minutes to warm up."

Houston is the Redskin link between past glories and present aspirations.He is the best player -- nudging out John Riggins -- on a rebuilding team that desperately clings to its quality athletes. His impact on the club is immeasurable. He is both its most respected talent and its most admired member.

If there is a leadership gap left by the departure of Billy Kilmer, it must be filled by Houston. No one else on the Redskins is regarded so highly by both the offensive and defensive players.

He has become the team's elder statesman, leading by doing.

"I just go out and work hard every day and try to lead my life as an example. I'm also truthful. If someone on the team asks me a question, I try to give them an honest answer. Things have changed. The team has changed, and it's different being old and almost everyone else is young.But that is football; I love it.

"I enjoy helping someone like Mark Murphy. Even in my second year, I'd try to help someone if they'd asked. It's for my good and for their good. We both want to win. And if he gets good enough to beat me out, great. I'll shake his hand, because he is a better man on the field. That is the only way to look at it."

"I don't think he's ever missed a game or a practice since I've been here," said new face safety Mark Murphy. "He's always the first one out and one of the last ones in. He's been in the league for years but he still practices hard and he never complains.

"How can you not admire a guy like that?I know I've tried to watch and learn as much as I can from him. But beyond that, he is a wonderful person. Everyone looks up to him. I respect him more than anyone on the team. He's the kind of person that every father wants his son to grow up to be."

Houston's brilliance begins with his natural gifts. Coach Jack Pardee says he is the prototype strong safety.

"You would see him on the field and want him right away," said Pardee. "You tell your scouts to get us someone who is 6-3, weighs about 200, can run like him and hit like him."

Houston attributes his success to things other than a model body.

"First of all, I pray a lot," he said. "I know what people think, but it's true. This has been God's will.

"You also have to have the desire to pay the price. Not at age 30 but when you are 21. You have to get plenty of rest and keep away from drugs and alcohol. And I really credit a lot of that to the fact I stay home. I can't remember the last time I was out alone without my wife."

Houston admits he has lost a step or two, but because of the increasing use of zone defenses and his own drive for perfection, he has been able to adapt.

"I don't need to run as much during games because of the zones," he said. "I also know now I can't afford to make mistakes. Before, I could be wrong and use my quickness to make up for it. Now if I am wrong, I get beat. So I have to know my keys and execute my fundamentals exactly.

"And I still hate to get beat, even in practice. I may not show outside, but I burn inside. Maybe that's why I still like to practice. It's a challenge even after all these years.

"Six years ago, when I was with Houston and we were playing on AstroTurf, I felt I had just one more year. But when I came here and I got into a good flexibility (stretching) program, I began to pick up speed. Flexibility has saved me. It takes hours, in the offseason and at night, but it's kept me in the league."

Houston's diligence has not been unnoticed.

"He's conscientous," said assistant coach Richie Petitbon, a former all-pro defensive back. "He goes about his job as work, not as some lark. That's important. It's serious business and he knows it.

"He very seldom has emotional highs and lows. He's a model of consistency. He really never has a bad game, maybe they all aren't sensational but never terrible. You know that you are going to get a certain level of performance from him every game. From a coach's standpoint, that is important.

"You don't fool the players. You are either a football player or you aren't. That's why he doesn't have to be talkative. When he goes out and plays so well, that naturally picks everyone else up too."

To beat Houston, says tight end Jean Fugett, "you have to do more than just the normal things."

"When I was with Dallas, he was the toughest safety in the league to play," said Fugett, who had to challenge Houston as a Cowboy before joining Washington. "It wasn't just that he played the pass well, but there is no one better forcing the run.

"He has this way of hiding from the pulling guards and then stepping into the hole and popping the runner.

"He's getting older and older and the tight ends are getting better and bigger, but you'd never notice it the way he is playing. He makes it look so easy.

"He does everything right. He keeps good position, he knows his keys so well and he has all that experience. And he has such long arms. You have to beat him by two steps, not one, because of those arms. Otherwise he always gets a hand in to block the pass.

Smart teams do the right thing. They keep away from him.Why challenge someone that good?"

In his later years, Houston also has become a teacher. Murphy is his prize pupil.

"He's been so helpful," said Murphy. "We talk a lot. And I watch him a lot. Why not? He's the best and if you can be as good as him, it sure would be nice.

"Playing along side of him pushes you. You don't want to let him down. He lets me know where he likes to be in every coverage and where I'd be the most help to him. We go over receivers before every game, we talk about them and try to analyze what they do.

"He's shown me that you can't let down, that you can't go to pieces if you get beat. He's just so steady, he doesn't let you be another way."

No one is sure how long Houston can maintain this level of excellence.

"He wants to go out as a good player and not hang on," said Pardee. "It isn't as easy for him as it was. Like anyone else with age, I'm sure his legs are more tired. And his eyes bother him in night games and he's had some migraine headache problems.

"But experience and intelligence can make up for some of your physical skills going downhill. He's the kind of guy you never worry about. You know what he is going to do for you every Sunday."