Just when you thought the sports calendar couldn't get busier — the World Series, NFL regular season approaching half-way point, the NHL season underway — it can. Ahead of the new NBA season, which begins Tuesday, we'll look at a couple of valuable knees and a couple of legacies. Derrick Rose in Chicago and Russell Westbrook are both coming back from injury and surgery — and their performances could determine whether or not Miami wins a third straight title. Meanwhile, Lebron James tries to build his legacy, and Kobe Bryant tries to retain his.