San Diego Chargers running back Chuck Muncie says he had a $200-a-week cocaine habit and purchased cocaine at least twice from his former New Orleans Saints teammate, accused cocaine distributor Mike Strachan, The New Orleans Times-Picayune, States-Item reported yesterday.

Muncie, who was traded to San Diego in 1980, told the newspaper he has curtailed his cocaine usage since joining the Chargers and that he has improved his play. But he said he still has a problem with alcohol and marijuana, and he plans to seek treatment in a detoxification center in about a week.

He paid Strachan with personal checks for the cocaine, some of which he shared with his New Orleans teammates, Muncie said. Strachan has been indicted on one count of conspiracy to distribute cocaine and 11 counts of distributing it.

Last week the Times-Picayune, States-Item quoted unnamed sources as saying a dozen Saints and former Saints, including George Rogers, the National Football League's leading rusher last year, were under investigation for having purchased cocaine from Strachan .

Muncie said that he and Strachan were close friends and roomed together on road trips for more than four years. He said he believes Strachan was acting as a middleman as a favor to other players.

"I never saw Mike out to get money, to make money," Muncie said. Strachan was cut by the Saints in 1981.

Muncie said he begain to use cocaine while a student at the University of California at Berkeley shortly before the Saints drafted him as their first pick in 1976. His cocaine use grew until it affected his play in 1979, he said.

"I was getting to the point in my career when I knew I had to do something. . . I had to stop doing a lot of things. I couldn't bring myself to just go and stop. It was a thing where I had to slow down and take it step by step . . ."

In another development, a former Miami Dolphins defensive end, John Andrews, claimed team owner Joe Robbie released him in 1977 in a purge of suspected drug users and then kept him out of professional football, United Press International reported.

Andrews' comments came in response to a story in the Fort Lauderdale News that quoted Robbie as saying drug abuse among some of the players probably contributed to the team's dismal 1976 season when the Dolphins went 6-8, their worst ever under Coach Don Shula.