Redskin Coach Jack Pardee said yesterday he is interested in obtaining disgruntled Baltimore Colt running back Lydell Mitchell, but he added the Redskins "aren't in a preferential trading position."

Pardee said his team's lack of high draft choices the next couple of years and the makeup of his present squad make it doubtful that the Redskins can offer the Colts what they would want for Mitchell.

Pardee said the Redskins have not contacted the Colts about Mitchell.

"Sure we're interested in him, though," Pardee said, "and we'd love to have him, but there would be a lot of compensation involved.

"They have put the word out around the league that he could be available. I just don't know how sincere they are about trading him."

Talk about running backs was prevalent at Redskin Park yesterday because, after waiving Tommy Reamon Tuesday, the Redskins are down to four running backs and Pardee said he prefers to go with five.

"It's tough getting by with only four," Pardee said.

Pardee mentioned that bringing back Calvin Hill remains a possibility.

The four running backs in camp are starters Mike Thomas and John Riggins and reserves Clarence Harmon and Tony Green.

Green probably will be the kick and punt returner and Harmon is an able body at either fullback or halfback.

Thomas is the key to the Redskins' running attack, and yesterday Pardee was high in praise of him.

"If he'll practice and play every day like he did today," Pardee said, "he'll be great. I don't mean he'll be good, I mean he'll be great. The way he worked today was the way Walter Payton worked."

"I feel fantastic" Thomas said. "I feel better this year than ever before. When (George) Allen was here it was a pressure thing all the time and it was tough to deal with week after week. I'm more relaxed now and I just feel better."

Thomas gained 919 yards as a rookie in 1975 and followed that with a 1,191 year. He tapered off to 806 yards and a 3.5 average last season.

"My legs are stronger this year, my upper body is stronger, I'm reading defenses better and I'm catching the ball better," Thomas said.

"We're going to bring some more excitement into the game. It won't be boring."

Is Thomas perhaps looking over his shoulder at Mitchell?

"I've heard about the possibility of Lydell coming here," Thomas said. "If he does, we'll just have to deal with it then. But I still think Calvin is coming back, that's how optimistic I am."

Whether it's Mitchell, Hill, or not, Thomas feels the Redskins will pick up another running back soon.

"It's going to be a long, hard season," Thomas said. "That's one reason I was so surprised when they cut Tommy. He was running and catching real well, but . . . "

Harmon, a free agent from Mississippi State, became a starter last year when Riggins and Bob Brunet were injured in the fifth game of the season.

In nine games as a starter, he gained 310 yards. With Thomas and Riggins having carried the ball only 27 times between them so far this preseason, Harmon is the club's leading rusher and pass receiver in the preseason, and Pardee has confidence enough to use him at either of the running back positions.

Harmon also performs on all the specialty teams, except on field goals.

Doing that and playing two positions makes him perhaps the most worked Redskin.

"The system is easy," he said.

Harmon, too, was surprised at Reamon's release and is expecting the Redskins to pick up another running back.

"It'll be tough for another back to learn the system, though," he said. "It'll probably take him at least two weeks to get it down," Harmon said.

That is a major reason why Pardee wants to acquire someome soon if he is going to bring in a new back.

Quarterbacks Joe Theismann and Billy Kilmer worked with the first unit in practice yesterday and Pardee said each will play a half in Friday's final preseason game here against the Atlanta Falcons . . . Kilmer razzle-dazzled his mates in practice yesterday when he looed to his left and threw a perfect blind pass to a receiver on his right. He would have made Pete Maravich proud . . . Yesterday also was pardee's first look at newcomers Ricky Thompson (wide receiver) and Greg McCrary (tight end).