Alex Rodriguez survived the blistering biography by Sports Illustrated’s Selena Roberts, “A-Rod: The Many Lives of Alex Rodriguez,” which revealed he once tested positive for a performance-enhancing drug. But while the slugger triumphs in the postseason with his torrid home-run hitting, there’s a new cloud on the horizon: another unauthorized bio, this one by Pulitzer Prize-winning Richard Ben Cramer, who ripped Joe DiMaggio to shreds in a 2000 book. Cramer depicted the Yankee Clipper as a “cold, small, often nasty, uncaring, resentful, self-centered man, a man of public grace and private misery who broke friendships, shunned family and chased money with the same focused energies he once harnessed to run down fly balls. It’s not a pretty picture,” one reviewer said. According to the buzz at DaTommaso restaurant, Cramer has spent several years on the A-Rod book and is still working on it.