Pitcher Floyd Youmans of the Montreal Expos is being investigated by the office of Baseball Commissioner Peter Ueberroth, the team said.

"The investigation has been going on for three or four days," Expos president Claude Brochu said Thursday.

Brochu refused to say whether the investigation began after Youmans submitted a urine sample. Youmans, 24, spent a month in an alcohol rehabilitation clinic last winter after not pitching during the club's pennant drive in September.