Let’s hope this isn’t a second career for retired pitching great Roger Clemens. “The Rocket” penned a piece in Friday’s Houston Chronicle bidding farewell to Mariano Rivera. His final line encouraged Rivera to return to the mound next year. “When you’re sitting at home next May and the Yankees are in need of a closer remember … anybody can retire once!” Clemens wrote. Clemens who pitched for the Red Sox Blue Jays Yankees and Astros during his 24-year career came out of retirement several times in his career. Speculation over whether or not he would return to baseball was an annual offseason ritual. In May 2007 after three seasons with the Astros Clemens showed up in George Steinbrenner’s box at Yankee Stadium during a game and announced he’d be un-retiring – again.