Brooklyn rolled over for the first time under new coach Jordi Fernandez, a 139-114 capitulation against the Celtics before a sellout crowd of 18,112 at Barclays Center. And Fernandez wasn’t making any excuses for their effort, because it was inexcusable. “I’m OK with losing, but I’m not okay with, at one point in the game, not fighting,” Fernandez said. “You can never, ever, ever, quit or look defeated, whatever the case may be. We have to continue to do things the right way, and if one night the other team is better than you, then you gotta respect it. But this — flashes of not doing the right things — this is not what we want to be at all. “And we haven’t done it. It’s just easier against adversity. Whatever you want to call ‘adversity,’ to me, it’s all excuses. The NBA, it is what it is. Everybody deals with stuff and you don’t want to be like, finding the excuse. We have more than enough to be better than this. To me, that’s plain and simple.”