When the Redskins tabbed tight end Don Warren as their first choice in last spring's draft, they hoped he eventually would supply insurance at a spot that had given them so many problems in 1978.

But not even General Manager Bobby Beathard could envision his fourthround selection paying dividends this quickly.

Just three weeks into this first NFL season, Warren could wind up playing full time Monday night against the Giants unless Jean Fugett can over come a strained knee well enough to take his regular turn.

Warren has been alternating with Fugett, a former Pro Bowler, as the Redskins employ their tight ends to bring in plays. Considering Fugett's past record, it already was an accomplishment for Warren to have earned part-time duty.

And now, with Fugett's injury, the Redskins hope this early faith in the rookie will pay off. Coach Jack Pardee only has to remember back to the middle of last season, when Fugett could not practice because of a knee problem and the club was left with just one inexperienced tight end, Reggie Haynes, who now is on injured reserve.

"We had to improve that position," said Pardee."It was hard conducting practices without enough tight ends and, with Jean struggling, it made it hard to get what we wanted out of the position."

There also was the matter of Fugett's silent war with team management. He hardly is Beathard's favorite player and although he is in the option season of his contract, the two sides are not talking. It is apparent he is playing out his final year with the idea of at least testing the league money coffers in the off-season.

Sharing time with Warren will not help Fugett's bargaining position, but giving the rookie added playing time does protect the Redskins in case Fugett is not back in 1980.

The team also appears to be hoping that competition will dirve Fugett to work harder. Beathard's major criticism of the tight end has been his sometimes lacadaisical attitude.

Fugett has slimmed down to a svelte 228 and alread has caught three thouchdown passes to start what he thinks will be a fine individual year for him.

But yesterday he was loosening up his strained knee (not the one operated on in the offseason) by walking around the practice field. And Warren was taking a full turn with the first unit.

"At least we won't be sending out an untried player Monday if Jean can't play," said Pardee. "Don is the kind of player who should get better every day. He has a lot of room for improvement.

"But the one thing about him is he goes 100 percent. He does everything all out. Like on a block, he may not get it all but he will make contact. He'll have at least a partial block. As soon as he learns to finish better, he'll make ever more progress."

Warren is the first to admit he is not in Fugett's class yet, especially as a receiver. At this point, the former San Diego State player is sure about just one aspect of his fledgling career.

"I just know that I belong here, on this level," he said. "Four years ago, if someone said I'd be a pro I would have laughed. But I'm here now and I have to keep working harder and harder to make myself better.

"I'd like to be bigger and stronger. That's something I realized right away. You look around at all the big people and it's not hard to figure that out. But that doesn't mean I can't contribute something right now."

Warren, no 98-pound weakling, currently is 6-foot-4 and 225 pounds. But he would like to put on 10 pounds and improve his strength so he can better handle the demanding blocking role the tight end fulfills in the Redskin offensive scheme.

"Don't get me wrong, I think I can make a contribution right now," he said."I'm not kissing off my rookie season at all.

"It's just I can see so much room for improvement, in every area. For such a long time, I was just trying to survive. I really didn't even think I would make the final cut.

"At least things are starting to make sense now. For the first four exhibition games it was hard. There was so much to learn and remember, it was a struggle. I feel better about my duties now."

Warren is just as surprised with his unexpected playing time. He says he was told when he signed with the team "that if I hustled and put out, I could play this year," but he never envisioned so much happening so fast.

"I haven't really done that well in any single area," he said. "I've tried as hard as I could. That's something my dad told me but I didn't realize he was right until junior college. Now I go all out and hope it will be enough.

"I've just been fortunate that I've gotten some time. Most of the other rookies haven't had the same kind of chance. It's the best way to learn, out on the field in games. I have to make the most of it."

Warren had only one reception during the preseason and he was shut out in the opener against Houston. But last week against Detroit, he caught two Joe Theismann attempts, including one that he almost turned into a touchdown.

"I wasn't the primary receiver on the play," he said. "I was supposed to be clearing out an area down field for the halfback. But their guy went with the wrong man and left me open."

Warren caught the ball on the Detroit 10 and turned, expecting to fight off a tackler. Instead, the closest Lion was at least five yards away.

"I don't know why but I decided to run over him," he said. "In college, I used to put moves on people but since he was the only guy around, I went after him." Warren lost and was tackled at the five.

Still, those catches were a first step in the pro-education of Don Warren, who once thought "way back in junior college that I had to know everything there was about tight end."

Defensive tackle Dave Butz dressed for the first time this week but, like Fugett, spent the practice watching and walking. Fugett did participate in some early half-speed drills.