Washington Redskins linebacker Mel Kaufman was admitted to Arlington Hospital yesterday morning and placed in traction when he complained of loss of feeling, tingling and severe pain in his upper right leg.

Kaufman, the team's starting left linebacker, was expected to stay in the hospital overnight for observation and await the results of several tests. Early indications were he had a pinched nerve in his lower back, Kaufman said by telephone from his hospital room. His status for the team's regular season opener Sunday at 1 p.m. at RFK Stadium against Philadelphia was listed as questionable (50-50) and the coaches were preparing to start first-year linebacker Anthony Copeland if Kaufman is unable to play.

Running back Kelvin Bryant strained his right calf muscle Thursday in practice and missed yesterday's final full-scale workout for the Eagles. Head trainer Bubba Tyer said the strain was "mild" and would not keep Bryant out of the game. "He'll definitely play," Tyer said.

The problems of Kaufman and Bryant are the latest in a long string of injuries to Redskins starters and key reserves. Ten players who would start or play key backup roles are now injured. Four have been placed on injured reserve and are out for sure: tight end Clint Didier (pulled left hamstring); offensive tackle Mark May (partially torn right knee ligament); middle linebacker Neal Olkewicz (right knee cartilage surgery) and tight end Terry Orr (severely bruised left shoulder).

Most of the other six are expected to play, but most likely in limited roles. Running back George Rogers (sprained left big toe) is expected to start, Coach Joe Gibbs said, but how much he will play is unknown. Defensive end Dexter Manley (partially torn right knee ligament) practiced again yesterday at Redskin Park and is likely to play on passing downs. Right cornerback Tim Morrison (bruised right calf and ankle) is still not at full strength and probably will be replaced by Barry Wilburn in the starting lineup. Reserve linebacker Ravin Caldwell (abdominal strain) has not practiced as much as usual this week. Add to this Kaufman's and Bryant's injuries, and Gibbs seemed to have every reason to plunge into rather severe panic less than 48 hours before Sunday's game.

"Right now, I'm really concerned," Gibbs said. "Some of our veterans are going to have to play the best they can play and lead us because this is the most injuries we've ever had, particularly for an opener. It's got me really concerned."

Kaufman said he first felt pain in his right leg Wednesday in practice, but received some medication and felt better when he practiced Wednesday. But Thursday night at home, the pain shot from his groin to his knee, and became "unbearable," he said.

"I ended up getting two hours of sleep, only it was not really sleep. It was just kind of a daze. The pain got progressively worse. It almost brought tears to my eyes. The pain was in my nerves. It was constant and throbbing."

Kaufman arrived at Redskin Park at 7 a.m. yesterday, "as soon as someone else would be around," he said, and was taken to Arlington Hospital. He was placed in traction for his lower body and underwent a series of tests, including bone scans, a CAT scan and X-rays, he said. Results of those tests were not available as of early evening.

Kaufman, considered by some to be the Redskins' best linebacker the last several seasons, missed all but two games of the 1986 season with a ruptured right Achilles' tendon. He suffered the injury Sept. 14 against the Los Angeles Raiders. Kaufman, 29, returned in training camp this summer and looked good. He regained his starting job with ease and appeared completely healthy before this week.

"It's frustrating, to say the least," Kaufman said. "I'm just going to have to overcome this, too."

Kaufman and Tyer both said the Achilles' tendon and upper leg injuries are not related. "We're going to investigate the origin of the pain," Tyer said. "We don't know what it is. It's like a pinched nerve . . . If the symptoms clear, we could leave him {in the hospital} all day {today} and get him out and he could play on Sunday if the doctors clear it."

Copeland practiced in Kaufman's place yesterday. On Monday, Copeland was released, then reacquired the following day when a roster spot was created by an injured-reserve move. All along, the Redskins wanted to keep Copeland, who was on injured reserve last season. If Copeland starts, linebackers coach and defensive coordinator Larry Peccatiello said he is confident Copeland will do well.

"We'd start Anthony because Ravin didn't have a lot of time in practice," Peccatiello said. "He should be ready. We've been working since July 15 . . . We're just in the dark on what will happen right now. Mel's been having a good camp. Naturally, it's a disappointment. That's an understatement, to say the least."

As for Bryant, Gibbs said he was "real" concerned when he found out about the injury, but felt better about it yesterday. Bryant's calf was "sore but not swollen," Gibbs said. "We'll let him stay off of it. Hopefully, with a couple days' rest, he'll be okay."