The Redskins' hopes of beginning the second half of the season with a healthy team hit a major snag yesterday when guard Jeff Williams was hospitalized with a severaly bruised right thigh.

Williams considered Washington's best lineman and a key factor in its improved running game missed six weeks of training camp with a similar injury to his left thigh. It is unlikely he will play in Sunday's game against Minnesota in RFK Stadium, although the club is hoping he won't be sidelined again for six weeks.

"It just doesn't seem too good right now," Coach Jack Pardee said. "I just hope it won't be as bad as they (the doctors) are saying. There is lots of swelling. I sure hope it doesn't turn out to be like the one in training camp, but this one is reacting just like that one did at first."

Williams, who will probably be replaced by veteran Dan Nugent, suffered a pinched nerve in his neck late in Sunday's game against New Orleans. It was that injury that forced him out of the contest, not the thigh bruise, which also was treated by the club's medical staff in the training room.

However, Williams later realized the thigh was swelling quickly. He went to the emergency room at Sibley Hospital last Sunday night. He remained in the hospital yesterday for further treatment.

"We got on this one quicker than the last one," Pardee said, "and maybe that will help. The first bruise was in the middle of his thigh and this one is on the side. We just have to hope the treatements will work real fast."

Nugent, a former starter, was waived before the season after trying to return from 1979 back surgery. He was re-signed before that Sept. 21 game with Oakland and started the Oct. 13 game against Denver for injured Ron Saul.

"We'll probably go with Dan," Pardee said. "He played well for Jeff against New Orleans and I think he can do the job. But Fred Dean has played everywhere for us and I'm reserving judgment whether to change my mind later in the week and go with Fred."

The injury to Williams coincides with the return of tackle Terry Hermeling, coming off an operation of his thumb, Dean played Sunday in place of Hermeling, who got in for a couple of plays when Dean was shaken up.

Injuries played a part in the Redskins' 3-5 start. Instead of being in contention for a playoff spot and a division title, as they had anticipated they might be, they are fighting to climb to .500 over the last eight games.

"We got ourselves in a hole losing five of our first six games," Pardee admitted. "We know you have to win the second half of the season if you have any playoff aspirations. "But you have to be next to insane with a 3-5 record to talk about the playoffs. If we can work our way back to a contending position, then we'll worry about it."

Over the last part of the schedule, Washington faces four straight games against Philadelphia (7-1), Dallas (6-2), Atlanta (5-3) and San Diego (5-3). Pardee knows his team must beat both Minnesota (3-5) and Chicago (3-5) the next two weeks.

"We have to beat the teams we are bunched with and then upset a few that are supposed to be better than we are," Pardee said. "But I feel the same now about this team as I did about last year's club. We aren't all that talented, but we are good enough to play with anyone we meet. We just have to realize there isn't much leeway."

For the Redskins to reverse their current record, Pardee said his team must do two things differently: score more touchdowns instead of field goals, and stop the rush.

"One thing, we have to hold onto passes. We can't drop them like we did against New Orleans. We can't mess up the opportunities we have, especially against the good teams. You don't get many chances in those games and you have to make every one count. "We have to be able to react to the run better when we are in mainly pass defenses."

The Redskins are averaging 319 total yards a game, and they've managed to penetrate the 30-yard line 31 times. But they've scored only 17 of those occasions (55 percent), and just 10 of those scores have been touchdowns. Washington has scored 14 TDs in all, three fewer than at this point last season.

"We're moving the ball okay, and Joe (Theismann) is throwing well. Art Monk (29 catches) is getting better every week and Wilbur Jackson (382 yards) is becoming as dependable as you could want," Pardee said. "The parts are there, especially now that Mark (Moseley) is back in the field goal groove. We just have to put the finishing touches on our drives."

Four opponent rushers have gained at least 107 yards against Washington this season, including little-known Jim Jodat and Jimmie Rogers. Teams are taking advantage of the front four's lack of quickness and Pardee's commitment to overplaying the pass.,

"People are running successfully against are nickel defenses and we have to tighten up a bit," he said. "But we are taking calculated risks. If we don't match up the way we are trying and if we play a lot of zone and not go with man-to-man coverage, the good quarterbacks will knock the eyes out of the defense. If we played more zone, we'd be able to force better on runs, but you have to be a lot better than the teams you are playing to stay cautious.

"We need to go after people. The kind of running gains that New Orleans and Seattle were getting on us shouldn't beat us and wouldn't have, if our offense was playing like it is now. If teams are going to rely on quarterback sneaks to beat us, well, I'll take my chances with that."

Fullback Rickey Claitt, once the team's leading rusher, who did not carry the ball against New Orleans, will play more. "But I'm not sure how or when," Pardee said. "When he hurt his ankle, he got behind and he isn't as advanced as the others in picking up blitzes and running some of our new offensive stuff. We can't risk having our quarterback killed" . . . Pardee again praised linebacker Rich Milot, who had two interceptions, a sack and seven tackles against New Orleans. But he was less than pleased with both Bobby Hammond and John McDaniel, both of whom dropped important passes Sunday.