– On Opening Day Monday, baseball's new commissioner, Rob Manfred, stood with reporters before the New York Mets played the Washington Nationals in the nation's capital and ruminated on a sudden run of positive drug tests in his sport, all of them surprisingly involving Stanozolol, an old, easily detectable steroid.

Manfred said the fact that the same drug had shown up in positive tests for Twins pitcher Ervin Santana, Atlanta pitcher Arodys Vizcaino and Seattle pitcher David Rollins had made him suspicious. He wondered whether the players had obtained the substance from the same source, and whether the sport could be confronting something akin to the 2013 Biogenesis scandal.

Manfred added he had already assigned investigators to look for links in the three positive tests, but so far, none had been found.

Baseball is sure to keep looking, as a fourth positive test for Stanozolol was announced Saturday, this one involving ailing Mets closer Jenrry Mejia.

The often-injured Mejia, 25, had been placed on the disabled list Tuesday with what was described as inflammation in his right elbow. That condition had been expected to keep him sidelined for several weeks, but now Mejia will be suspended for 80 games and cannot return until July.

Stanozolol is sold under the name Winstrol and is popular with body builders. It is notable for being the drug that cost Canadian sprinter Ben Johnson a gold medal and a world record time in the 100 meters at the 1988 Seoul Olympics.

Asked Saturday if the Major League Baseball Players Association was worried there was a connection to the four positive tests, union spokesman Greg Bouris said: "We are always concerned when there's a positive test, regardless of the substance."

Mejia, 25, will lose $1,134,426 of his $2,595,000 salary because of the suspension.

It is a body blow to the Mets, who are hoping that 2015 will be a turnaround year but have already seen their pitching staff decimated by injuries. The news of Mejia's suspension broke Saturday evening, while the Mets were taking batting practice before a 5-3 loss to the Braves.

Manager Terry Collins met with the news media with a glum face and his arms crossed.

"It happens in the business, but it's a little damper," Collins said. "I'm going to be honest. I love this kid. We challenged this guy last year; he stepped up and did a great job for us. Certainly this is a disappointment. I always look at it as: I understand everything about it, I really do. But you know what? There's 24 other guys in that locker room who need him, too. That's why it's really disappointing."

That was the general reaction in the clubhouse: disappointment.

"Not only do you cost yourself 80 games and don't get paid, but you're hurting everybody in here," David Wright said. "You're letting down your teammates. That probably means just as much, if not more, than hurting yourself."

Mejia issued a statement through the players' association and said he would accept his punishment but also added, "I can honestly say I have no idea how a banned substance ended up in my system." He apologized to the Mets, his teammates, the fans and his family.

For the trouble Mejia had caused, Collins refused to call him "selfish." Then he was asked, in this day and age, considering how meticulous players are in their training, how could they not know what substances entered their bodies?

"I know what goes in mine," he said, laughing. "I can't answer for everybody."

The Associated Press contributed to this report.