Prankster calling media saying Giambi fails steroid test

Jason Giambi's breakout month -- 14 homers, 24 RBI in July -- apparently has given rise to a prank caller.

A man has been calling media outlets, claiming to be the assistant to Yankees president Randy Levine, with information that Giambi had tested positive for steroids, the New York Daily News reported Thursday.

In response, Yankees officials have asked the New York Police Department to find the caller, who claimed Major League Baseball would announce the failed test Friday.

A team and a league source both told the Daily News that Giambi, who has been tested at least once this season, has not failed MLB's steroid tests.

"If he had [tested positive], everybody would know," one source told the paper. "He's been clean."

The team source also said Levine does not have a male assistant.

"I'm very happy for him. He's gone through a great deal, worked very hard, has proven to be a winner and I'm proud of him. I'm proud of Jason Giambi," George Steinbrenner said in a statement received by the paper.

Giambi hit 14 homers in July, becoming the first Yankee to hit
that many in a month since Mickey Mantle in 1961. He was hitting a
season-low .195 on May 9, but has raised his average to .284.