As Peter Ueberroth, the commissioner of baseball, seeks to implement mandatory drug testing among major league players, he might consider looking to World Cup soccer for guidelines.

At every match of this 13th World Cup, there are random drug tests at halftime.

But then again, World Cup participants do not have the benefit of a players union, and Ueberroth's power does not begin to approach that of FIFA, the international soccer federation that controls the sport.

FIFA, like the International Olympic Committee, publishes a long list of banned substances. At the Olympics, all medal winners are tested for drugs. At the World Cup, two players from each team are randomly selected at halftime to provide urine samples.

"If a player is found to have taken one of the forbidden substances, we can fine him or suspend him. Each case is taken on its own merits," said Harry Cavan, FIFA senior vice president.

"We have found this system to be an excellent deterrent," said FIFA official Rafael de Castillo. "We feel that there is not a substantial problem with controlled substances, but this can discourage and weed out any violators."

FIFA has tested players for drugs since the 1966 World Cup in England. At the 1978 Cup in Argentina, Willie Johnstone of Scotland was banned for taking stimulants, the only time a player has been found in violation of the regulations.

The list of banned substances includes analgesic narcotics such as heroin and morphine, cocaine and amphetamines. There are strictures against even mild stimulants such as caffeine (but a player would have to drink 30 cups of coffee before a match to go over the caffeine limit).

If a player is on medication, his team's doctor must inform FIFA 72 hours before a match and tell the federation why the drug is being used.