Poor Alex Rodriguez: You're the highest-paid baseball player in the history of the game and you can't get a little action on the side without the papers making a federal case out of it? Mickey Mantle must be spinning in his grave like a chunk of lamb on a gyro machine. Anyway, the Associated Press notes yesterday's Post headline on the story ("Stray-Rod") and ranks it up there with some of the all-time classics (e.g., "Headless Body in Topless Bar") of the genre. Fortunately, the A.P. tells us that A-Rod's teammates and coaches are fully behind him.