The bad back that has plagued Steve Nash his entire career has knocked him out for the entire season before it even begins, the Lakers announced Thursday night. Nash suffered the latest re-aggravation—I shit you not—while carrying some luggage. The Lakers mortgaged much of their future to acquire Nash in 2012, agreeing to a sign-and-trade with Phoenix that saw them ship off two first-round and two second-round picks, and signing an aged Nash to a three-year, $27-million deal. He only played in 50 games that disastrous first season, when paired with Dwight Howard, Pau Gasol, and Kobe Bryant, he was expected to help lead the Lakers to a championship. Instead, the Lakers got swept in the first round of the playoffs. There was a lot of speculation that Nash would retire after he missed…