Commissioner Pete Rozelle says he fears illegal drug use in the National Football League "could be a larger problem for us than it is in society." That view is not shared by the head of the NFL Players Association, who said yesterday that estimates of drug use by players are probably exaggerated.

Rozelle was responding to an assessment by former all-pro defensive end Carl Eller, who said that 20 to 25 percent of the players in the league "are getting into the problem stage" with drugs and alcohol. Rozelle told the New York Daily News that he had discussed the NFL drug situation with Eller and revised his opinion that drugs were not a serious problem in the league.

Ed Garvey, executive director of the NFLPA, said Eller's estimates are too high. "We just think it's nuts to talk about 20 to 25 percent of the players being on drugs," he said.

"It seems everyone has a vested interest in this. (Rep.) Leo Zeferetti (D-N.Y.) wants to have hearings and get some publicity. Carl Eller wants the union and management to fund him to go around talking about drugs and Pete Rozelle has a public relations problem."

Zeferetti, chairman of the House Select Committee on Narcotics Abuse and Control, plans to hold hearings on drug abuse in the NFL this summer.

In his comments, Rozelle did say that Eller, a former cocaine user who is a paid consultant to the league, "told us enough to indicate it's not a wave of drug abuse."

Eller told the News that up to 40 percent of the NFL players may have experimented with cocaine and that 20 to 25 percent "are getting into the problem stage as far as misuse of all kinds of drugs and alcohol."

Eller's comments followed publication in Sports Illustrated of a first-person account of cocaine abuse by Don Reese, a former defensive lineman for the Miami Dolphins, New Orleans Saints and San Diego Chargers.

In Austin, Tex., Saints Coach Bum Phillips said yesterday that he doesn't think cocaine use is a big problem in the NFL. But he admitted it would be hard for him to tell if players were using the drug when they are not in training.

"I'm sure some people do it," Phillips told United Press International, "but I don't see players high on cocaine during a game. You just can't do that stuff and play football at the same time . . .

"I always thought coke was something that came in a red and white can."

In St. Louis, former Cardinal defensive end Kirby Criswell was sentenced to five years in prison on federal drug charges yesterday by U.S. District Judge James Meredith who turned aside pleas by Criswell and his lawyer that he be placed on probation.

Criswell, 24, was convicted June 2 of conspiring to make the drug methamphetamine, a stimulant, and of possession of marijuana. Last week, the Cardinals put Criswell on recallable waivers.

After the sentencing, a shaken Criswell said he was shocked by the sentence and thought the judge was trying to make an example of him. He said he had a job lined up in his home town of Grinnell, Iowa. He was freed on $25,000 bond pending an appeal.

In Denver yesterday, David Thompson described his trade from the Nuggets to the Seattle SuperSonics "as a relief" after the publication of a press report focusing on his possible use of cocaine.

Thompson told the Seattle Post Intelligencer that he was unhappy with a recent article in the Denver Post. "That was pretty poor, especially the timing," Thompson said, referring to the story that said the SuperSonics' management had looked into rumors of his possible drug usage.

Zollie Volchok, president of the SuperSonics, said he believes Thompson "is free and clear of any problems . . . The NBA investigation has not found any evidence of a drug problem. It's just hearsay and reports of things two years ago or more."