New York -- A high ranking Major League Baseball official told USA Today that New York Yankees slugger Jason Giambi may be headed toward a suspension.

The official said Commissioner Bud Selig may suspend Giambi unless he agrees to cooperate with former U.S. Sen. George Mitchell's investigation into steroid use in baseball before next week, USA Today reported Thursday.

Selig announced last week that Giambi could avoid disciplinary action for comments on steroids he made to the newspaper if Giambi cooperates with the investigation within two weeks.

"Any admission regarding the use of illegal performance-enhancing substances, no matter how casual, must be taken seriously," he said. "It is in the best interests of baseball for everyone, including players, to cooperate with Senator Mitchell in his investigation so that Senator Mitchell can provide me with a complete, thorough report."

Selig's statements stem from an interview Giambi gave the newspaper in May.

"I was wrong for doing that stuff," Giambi said. "What we should have done a long time ago was stand up -- players, ownership, everybody -- and said, 'We made a mistake.'"

Copyright 2007 by United Press International.