Mike Krucek's long wait for his next pro start, which began midway through his rookie season with Pittsburgh, is about to end.

It's been four years since Kruczek last trotted onto the field at the beginning of an NFL game. But Sunday, he will be in the starting lineup for the Redskins against the Falcons in Atlanta.

Yesterday, Coach Jack Pardee finally acknowledged that "it looks like we probaby will go" with Kruczek over injured Joe Theismann in the Falcon game.

"If the hamstring hurts on Sunday like it does now, we won't even use Joe in an emergency situation," Pardee said. "It would really have to be an emergency to put him in. It's getting a little better every day, but it's still sore."

Theismann said yesterday his leg was too weak for him to play. The hamstring, hurt two weeks ago and reinjured against Dallas Sunday, has hemorrhaged slightly, the major reason why it has responded slowly to treatments this week.

"We are finally getting it to come around," Theismann said, pointing to the ugly bruise line on the inside of his leg. "I can finally start doing things on it, but it's weak. I think I should be okay next week, as long as I keep making progress on it."

If Kurczek didn't realize he would start before yesterday, he knew once practice was under way. Unlike last week, Kurczek ran the offense, except for a few snaps to backup Kim McQuilken. Theismann watched and slowly ran laps.

"I feel good about this week, real good," Kruczek said. "I knew last week that Joe was going to start. But not this time. When he said his leg really hurt, I knew it really hurt. He just doesn't talk about pain that much, so you know it had to be bugging him."

Kruczek tried last week not to let the indecision over the quarterback bother him, but it did.

"You are still human, no matter how hard you try to say it doen't make a difference," Kruczek said. It does. There is something about knowing what your role will be on Sunday that affects how you prepare.

"I'm really ready right now. Things are going to be alot different on Sunday than they were against Dallas. All the kinks have been worked out."

Krucek, who came to Washington during training camp for a seventh-round 1982 draft choice, realizes that all reserve quarterbacks inherit this unrealistic burden. "Comes with the territory," he said with a laugh. "i don't care how much you watch films and study, there is still no substitute for playing.

"Until last week, I hadn't worked with the first unit offense in practice all season, except for some two-minute drills. And I hadn't played a full quarter since training camp. You can't keep sharp that way."

Pardee admits he gambled all season that Theismann would get hurt, which meant Kruczek had little chance to stay sharp. That gamble backfired in the second half against Dallas, when Kruczek's lack of work hindered the Redskin offense and all but eliminated any passing from the play calling.

"It's difficult to keep one quarterback prepared, much less two," Pardee said. "So you make a decision to go with one most of the time. In this case, Mike needed all the work he could get in practice this week. He had to catch up a little.

"He'll be much better this time around. He's had more time, more snaps, he's improved on his formation calling, his fundamentals, those things you take for granted but that a quarterback has to work on to keep in proper form."

Kruczek last started in 1976, when Terry Bradshaw was hurt and the young rookie from Boston College directed the Steelers to six straight wins. yThat season, Coach Chuck Noll Gave both men equal practice time, a policy that changed during Kruczek's next three seasons with Pittsburgh.

"After that first year, Chuck gave Terry all the practice time," Kruczek said. "But it still was different. I knew Terry was going to get hurt a lot. He always did. So I knew I would play. I got into nine games two years ago and eight last year.

"Here, Joe never gets hurt. So you don't have a lot of hope about playing very much. You either win the starting job or you sit. He's so darn durable. But yet I'm still glad I'm here. There's more of a future here for me than in Pittsburgh.

"I'm not taking anything away from Joe, because he's a heck of a competitor, but Terry is the best quarterback in the league.He's on a level by himself. I feel here that if I play to the best of my ability, I could start next year. I never had that feeling in Pittsburgh. Terry was just too good.

"I can play in this league; there is no doubt in my mind about that," he said. "This offense is suited for me. I ran a lot of rollouts and sprints in college and that's what we have been concentrating on lately here."

Pardee activated rookie tackle Jerry Scanlan, a free agent from Hawaii . . . Defensive tackle Perry Brooks is hobbling on a sprained ankle and probably won't play Sunday. Karl Lorch will move to tackle on passing situations, taking Brooks' place, Pardee said.