Rodriguez admits to dabbling in steroids while with the Texas Rangers early in his career but the book, "A-Rod," disputes his claim that it ended there. It also claims the steroid usage may have begun in high school.
Jose Canseco, an ex-teammate and friend of Rodriguez, was quoted as saying said he believes him to still be using human growth hormone HGH.
Author Selena Roberts of Sports Illustrated, who broke the story that Rodriguez flunked a steroid screening in 2003, provides a highly unflattering portrait of a needy "me-firster" who had to have his ego constantly stroked, the New York Daily News said.
The book, published by HarperCollins, is scheduled to be released May 12.
Roberts writes that Yankee teammates kidded Rodriguez about his new-found bulk in 2005 after he put on 15 pounds in the off-season and seemed to develop round pectorals, a condition called gynecomastia, which reportedly can be caused by anabolic steroids.
"No one ever asked Alex directly (about steroids) that I know of, but there was a lot of suspicion in-house," an unnamed Yankee employee said.