For the second time this season, the Buffalo Bills' O.J. Simpson has raised the possibility that his career is at an end when he left Sunday night for a visit to Los Angeles, where he will have his left knee examined again.

Simpson left the Sunday game in Seattle in the first half after carrying the ball nine times for 32 yards. The sore knee, which has been bothering him for about a month, forced him out.

A Bill spokesman reported that the team orthomedist termed the injury a "derangement." The medical dictionary defines that as a "partial dislocation of the knee marked by great pain and spasms of the muscles."

The concern for the Bills is that, if surgery is necessary, Simpson may retire. He has said that he will retire after the 1978 season in nay case. He is 30 years old and in his ninth year.

In July, there was fear that Simpson's career might be ended by blurred vision in his left eye, which was attributed to a blow over the eye he suffered in October, 1976.

The running back was examined at Wilmer Eye Clinic at Johns Hopkins Unversity medical center and assured that the condition would clear up. The Bill spokesman said yesterday that it has not yet totally corrected itself but Simpson has not been complaining about it.

The spokesman discounted the significance of Simpson's trip to his home in Los Angeles, pointing out that he is due back in Buffalo Wednesday and tht it is believed to be more of a "family-oriented" trip."

He noted that Mrs. Simpson gave birth to a child about five weeks ago and that the running back wanted to see the baby again. Simpson flew home from a game at Denver when the child was born.

Still, the spokesman confirmed that Simpson has been unhappy with the team winning only one of six games. Rock bottom was hit Sunday when the Seattle expansion club trounced Buffalo, 56-7.

It was a tribute to Simpson's drawing power that Seattle hd its first sellout of the season, 61,180. Simpson is by far the biggest individual attraction in the league.

Simpson was quoted by the Associated Press in Seattle as saying tempers flared in the Bill dressing doom at halftime.

"When you get cleaned up, a few guys get very upset and they made it known. "Simpson said." The Seahawks came out ready, we came out flat. They picked up our blitzers and seemed to know what we were doing.

Simpson has said he wants to break the career rushing record of 12,312 yards held by Jim Brown of the Cleveland Browns. Simpson now has a career total of 10,134.

Rich Stadium, erected in 1973 and called "the house that O.J. built," would become a white elephant without him. The Bills' fortunes do not figure to improve much this year, with New England yet to be played twice, plus Baltimore, Oakland, Washington, the New York Jets and Miami.

Other teams showing slippage from where they were at the halfway mark last year ar Cincinnati, which was heading the AFC Central in 1976 and now is tied with Houston at the bottom at 3-4, and San Francisco, which has tumbled from first place in the NFC West to a tie for the bottom with New Orleans at 2-5.

Atlanta is the new success story, climbing from a tie with Seattle at 1-6 in that division last year to a tie with Los Angeles for first place at 4-3.

While Simpson is having his miseries, Walter Payton of Chicago is coming on quickly as a ground gainer-rushing for 205 yards on 23 attempts Sunday in a victory over Green Bay.

Lawrence McCutcheon gained 107 yards on 26 carries despite the upset of his Los Angeles Rams by New Orleans: Tony Galbreath gained 100 on 20 attempts for the Saints, and Clarence Davis rushed for 105 yards on 20 tries for the Raiders in their victory over Denver.

Big plays for touchdowns were scarce last week. Sammy White caught a pass from Fran Tarkenton for a 54-year touchdown in Minnesota's victory ove Atlanta: Stanely Morgan caught one for 52 yards from Steve Grogan as the Patroits defeated the Jets, and Greg Pruitt ran 78 yards from scrimmage for a score as Cleveland trounced Kansas City and took sole possession of first place in the AFC Central.