Major league teams are monitoring players during the period between when they are notified they must take a drug test and when they provide a urine sample, according to the New York Times.
The procedure was instituted in July 2005 and covers a period that can be up to several hours, the paper reported on its website Saturday night.
"Players may not be aware they're under observation, but we're watching," baseball executive vice president Rob Manfred was quoted as saying. "It doesn't mean we tell them we're watching."
Three general managers are monitors, 18 assistant general managers, four vice presidents, four directors of baseball operations. The title of the other wasn't disclosed.
The Arizona Diamondbacks put pitcher Randy Johnson and outfielders Carlos Quentin and Jeff DaVanon on the 15-day disabled list.
Johnson, who is returning from back surgery, was scheduled to make three minor league starts before joining the Diamondbacks' rotation in the third week of April.
Quentin, who has a shoulder injury, was backdated to March 23. He could be available April 7. There is no timetable for DaVanon, who has an ankle injury.
Oakland A's right-hander Esteban Loaiza was scratched from his scheduled start for the second time in three days and could begin the season on the disabled list because of tightness in his right shoulder blade.
Manager Bob Geren called the move possible, but Loaiza says he hopes it doesn't come to that and isn't ruling himself out to make his first start Thursday night against the Angels.
Pittsburgh Pirates second baseman Freddy Sanchez, last season's National League batting champion, was put on the 15-day disabled list, meaning he'll sit out at least four games.
Jose Castillo will start at second until Sanchez returns. Sanchez hasn't played in a major league exhibition game since he sprained his right knee turning a double play March 6.
The Tampa Devil Rays set their roster when Jorge Cantu, their starting second baseman the last two seasons, was optioned to triple-A Durham. His departure leaves the starting job to B.J. Upton, one of 11 Tampa Bay players who are on an opening-day roster for the first time. Designated hitter Greg Norton was put on the 15-day disabled list because of a right knee injury that will require surgery.
Although the stakes will be considerably lower, memories of the St. Louis Cardinals' Game 7 win in last year's National League championship series will be fresh when the teams play the 2007 opener tonight at St. Louis.