Of all the ideas to come out of the Rangers postmortem locker room on Saturday in Boston, maybe the most confounding was the admission the team was not ready to start their second-round series against the Bruins. By the time Game 5 had ended, the Blueshirts’ season was kaput, it was all too little, too late. Yet for them it wasn’t about what had just happened on the ice, but the mentality that got them into a 3-0 series hole that only three teams in NHL history have crawled out of. “It almost felt like we were waiting for something good to happen,” goaltender Henrik Lundqvist said, “and it took too long for something good to happen.” In Lundqvist’s 10-minute postgame interview, more than once he referenced the Game 4 fall-over gaffe from Boston goalie Tuukka Rask that gave the Rangers life and led them to the one win which kept them from getting swept. The energy gained after Rask’s mistake enlivened the Rangers, but by then it was an energy that went for naught. “At the beginning of the series, I just thought there was a lack of awareness, how high you have to be as you go into the second round with your level of play,” coach John Tortorella said. “As we went on, I thought we got better. I thought we got better the last two games. But I still think, you know, we’re out. They’re in.” That lack of awareness — or lack of assertiveness — did not just start last week. This whole lockout-shortened season had been a struggle for the Rangers, as they could never fully establish their identity in the wake of no real training camp and a condensed regular-season schedule. “I think it’s a rigorous training camp, and I think we spend a lot of time building a mindset within it,” Tortorella said. “We didn’t have that, but no other team had it either.” Last year, as they made their run to the conference final, the Rangers embodied their Black-and-Blueshirt mentality. They were hard to play against every night. They blocked shots by the score. They were physical. And somehow, more often than not, they found a way to get just enough scoring to get by in tight games.