“Tennis is the only sport I know of where you have your locker right next to your opponent. You see him naked.” Photo: Thomas Kierok/laif On a Monday in mid-August, 47-year-old Boris Becker is hobbling across the lobby of the Marriott in Mason, Ohio, where the pro-tennis caravan has pitched its tent for the last hard-court tune-up before the U.S. Open. If his shockingly reduced gait (owing to two hip replacements and a steel plate in his right ankle) is the cost of hurling his 215 pounds at passing shots like a goaltender, then it seems too high. But how do you set a fair price on seizing tennis immortality by winning Wimbledon at 17? Becker has been cooling his heels in Ohio for two days, waiting for Novak Djokovic, whom he coaches, to arrive from Montreal, but there’s no hint of impatience; in fact, after nearly two decades of wandering in the wilderness, his relief and pleasure at being back at the red-hot center of the game is palpable. In his white Puma shirt and loose-fitting slacks, the German champion carries himself like an old-school Brooklyn wiseguy crossed with a beloved head counselor on the first day of summer camp….