Running back Mike Thomas missed the first Redskin practice of the week yesterday because of an eye problem, but an ophthalmologist who examined him said he should be able to play Sunday against the St. Louis Cardinals.

Thomas was examined yesterday by Dr. Thomas Frey, who diagnosed the problem as "traumatic iritis of the left eye."

In a statement released by the Redskins, Dr. Frey said Thomas' problem was "caused by trauma, a hit or a contusion," and that he should be able to practice today. Dr. Frey was not available for further comment.

Thomas also was given medication for the problem, and will be reexamined Thursday.

Thomas was not available for comment last night bt several of his friends on the team said he told them he had been hit on the head during the Giant game Sunday and had been feeling twinges of pain in his eye.

Thomas also complained that his left eye was sensitive to light. He wore a game patch yesterday.

Thomas enjoyed his most productive day of the season against the Giants, with eight pass receptions and a critical one-yard touchdown run that allowed the Redskins to extend the game into an overtime period.

It was his first appearance at RFK Stadium since missing three games with a foot injury, and he was booed in pregame introductions.

His foot injury became a source of controversy when Thomas said publicly he had declined to take a pain-killing injection that would have allowed him to play. Thomas was criticized publicly and privately by some teammates and other team personnel who thought he could have played with the injury.

Fullback John Riggins also missed the 45 minute session yesterday designed mostly to go over new palys and shake out the hurts of Sunday's game.

Riggins sprained his right ankle late in the fourth quarter Sunday and spent yesterday in the training room receiving rehabilitative treatments.

"It's in pretty shape for a sprained ankle," Pardee said. "It's sore, and whether he plays is strictly a day-to-day thing. He could probably run straight ahead, and that being the case, in a couple of days, with a good tape job, he should be able to make cuts and do everything else."

Riggins said, "I should be able to play, but whether I can cut or not is going to be the deciding factor. Right now, I can't and that's the only thing I'm apprehensive about. But at least it's not swollen too bad.

"I probably won't practice tomorrow (Wednesday), maybe just try and jog on it. I won't try and do any cutting until Thursday or Friday, and that's when I'll be able to tell."

Center Ted Fritsch also was among the missing yesterday, though he was released from Sibley Hospital earlier in the day. Fritsch spend two nights at Sibley after he suffered three broken ribs against the Giants.

Though he missed practice, Fritsch was at Redskin Park later in the afternoon and said he though he would be able to snap on punts and placements. 'I won't know until I go out there and try it.

"I know I feel a heck of a lot better today than I did Sunday. I was having a hard time just breathing. But they've got me padded up pretty good right now and I think I'll be all right. The only thing I'm worried about is snezezing."

Pardee was making contingency palns in case Fritsch is not available Center bob Kuriel and offensive tackle Jim Harlan will be asked to practice snapping this week, and so will linebacker Chris Hanburger.

"Chris does it (snapping) goofing around all the time." Pardee said. "and just goofing around he's one of the best snappers we have.

"Last year, the Cardinals had Steve Jones, one of their offensive backs during it, and he did a great job for them. So size isn't the biggest factor, it's just how good you can make that snap."

Quarterback joe Theismann moved up to fifth among NFC quarterbacks with his 22 completions and no interceptions against the Giants . . . Riggins' 823 yards rushing ranks him fourth in the conference . . . Tony Green leads the NFC in kickoff returns with a 27.8 mark and is third in point returns with an 11.3 average . . The Redskins are ranked fifth in the NFC in total offense, sixth rushing and sixth passing and are ninth in overall defense 10 against the rush and eight-against the pass. The Cardinals are third in total offense, 11th rushing and second passing, and 14th in total defense, 14 the against the rush and fifth against the pass.