Trey Mancini stood at a locker at Globe Life Field, one that belonged to him only briefly before he had to leave it behind. The words came easily, but the emotions did not. The Orioles’ longest-tenured player was in a daze, trying to process that he would soon no longer hold that title. On Monday afternoon, the Orioles’ rebuild faced its toughest move yet, with Baltimore trading Mancini, a player who endeared himself to the fan base with his personality and perseverance while facing cancer, to the Houston Astros for a pair of prospects as part of a three-team deal also involving the Tampa Bay Rays. The deal comes a day before the MLB trade deadline and with the Orioles only three games out of a wild-card spot, beginning a three-game series against the Texas Rangers at 51-51 after a 16-9 July that featured a 10-game winning streak.