BROOKLYN, New York: The main event in a jam-packed fight card bringing elite boxing back to Brooklyn on Saturday was in jeopardy after “irregularities” in a drug test of Mexican veteran Erik Morales.

The random test was administered by the US Anti-Doping Agency (Usada).

“Usada informed Golden Boy Promotions Tuesday that there were ‘irregularities’ found in one of Erik Morales’ random drug tests,” Richard Schaefer, CEO of Golden Boy Promotions, said on Friday amid reports that Morales had tested positive for the banned steroid clenbuterol.

“We will now let the process play itself out without a rush to judgment. It is a matter of due process and that is how it will be handled. We will proceed forward with the event either way as we have a tremendous show planned for the evening.”

Morales, a four-time world champion, was scheduled to challenge light welterweight champion Danny Garcia, who is coming off a fourth-round stoppage of ex-champ Amir Khan in July that took his record of 24-0 with 15 knockouts.

The bout, one of four world title fights on the card at the new, $1 billion Barclays Center, is a rematch of their fight in March, in which Garcia earned a unanimous decision.

Both Garcia and Morales weighed-in on schedule on Friday, when the fight was tentatively still expected to go on.

The Barclays Center is the new home of the NBA’s Nets, who are moving this season from New Jersey to the New York borough.

It will stage the first major fights in Brooklyn since August 5, 1931, when Maxie Rosenbloom defeated Jimmy Slattery to retain the light heavyweight world title at Ebbets Field—the home of baseball’s then-Brooklyn Dodgers that no longer exists.

There was one other blow for the card on Friday as Pablo Cesar Cano failed to make weight for his World Boxing Association title clash with Brooklyn native Paulie Malignaggi, the reigning WBA champ.

That fight will still go on as a non-title bout.