Joe Theismann has seen the whites of the Cowboys' eyes across the scrimmage line, but he says "a game with Dallas is a Sunday stroll" compared with a tennis match he played against John Havlicek in a recent "Superstars" competition.

Theismann had his collarbone smashed by those same Cowboys on Thanksgiving Day, but he also will tell you that the memory of those wicked hits has not been the source of his nightmares over the last few months.

No, says Joe Theismann, superstar, "I go to bed at night and dream about the wall." The very same wall that starts off the "obstacle course," probably the most difficult event in "Superstars" competition which features some ofthe world's best athletes competing in a variety of different sports.

Lately, Theismann also has had some sweet dreams and, mostly, they center on cash. He already has won $27,000 and today he will start competing in Freeport, Bahams, for the "World Superstars" championship and as much as $40,000 more in prize money.

And so, Theismann has been training diligently for a made-for-television event that really can no longer be considered a gimmick, not when the monetary equivalent of a Super Bowl check is involved.

The "World Superstars" will be televised on a delayed basis April 1, by WJLA-TV-7 at 2 p.m.

Since early January, when he was invited to the first competition, Theismann has worked out parctically every day. He says he has driven himself harder training for "Superstars" than he ever has preparing for football.

Football still is his livelihood, but he admits the "Superstars" competition has given him a chance to show that he can be one of the best at whatever he sets his mind to.

"I took it serious from the very beginning," he said. "I didn't want to go down there and get embarrassed. I can say that right now I am in the best shape of my life. I'm in Ridiculously good shape.

It's a whole different world, though. Since football ended, I've lost six pounds, taken 2 1/2 inches off my waist and added an inch and a half to my chest."

The other day, Theismann went through his final tuneup for the world competition, a grueling workout that started at 11 a.m. and finished more than four hours later, with hardly any rest in between activities.

He began by playing three hard sets of tennis, then ran 2 1/2 miles wearing heavy hiking botts, rode a 10-speed bicycle for several miles through his neighborhood, did a series of 60-yeard wind sprints and finished with a strenuous calisthenics routine.

During his tennis match, a ball got caught in an overhang 15 feet above the court. And so, Theismann had a chance to do a bit of impromptu training for the obstacle course.

In a flash, he was climbing a steel girder like "Spiderman." Bring on that wall.

I'm ready," he said.

"The thing about this type of competition is that you just don't know how good the guys you are going against are. I'm confident, though."

But then Joe Theismann always is confident, although he admitted that staring across the tennis court at Havlicek a few weeks ago was unnerving.

"The pressure is almost unbearable," he said. "I have never been as nervous as I was when I was playing tennis against Havlicek.

"Pressure comes from within, and most pressure is brought on by doubt, lack of confidence or by a new experience. I've never had trouble with the first two.

"Iplay a team sport, and when you do that, you rely on each other. There's no team ndow. There's no team to share it with, and there's no one to blame. It's all on your own shoulders.

"Everything is lighthearted -- until the competition starts. And then, you're hard-pressed for a smile until it is over.

"I had a broken leg in 1972 and I hurt a lot against the Cowboys Thanksgiving Day when they broke one collarbone. But I've never experienced a moment of pain like I did in the last 20 yards of the half-mile run."

In the "World Superstars," Theismann is entered in the half-mile, the obstacle course, the 100-yard dash, bicycle riding, gymnastics and the soccer kick.

He will be up against defending champion Brian Budd, a Canadian Soccer player who won $39,400 last year and the overall championship. Other top competitors include Wayne Grimditch, a water skier, and Greg Pruitt, the Cleveland Brown tailback, both of whom finished ahead of Theismann in the U.S. "Superstars."

Theismann is realistic about his chances this weekend. "I just hope to survive," he said, admitting that Budd seems unbeatable.

But Theismann's non-football athletic pursuits will continue after "Superstars." Next month, he will compete in a $58,000 professional athletes racquetball tournament in San dDiego.

"Now, recquetball, that's my game," said Theismann, truly a man for all sports.