The NBA’s 2013-14 season is still months from tipping off and yet it feels like a couple of teams have already dropped the ball. To their credit though it wasn’t intentional. The Boston Celtics released their regular season schedule on Tuesday with several key dates standing out including four matchups with the suddenly intriguing Brooklyn Nets. Why do we all care about those? You know why by now. On Dec. 10 the C’s will travel south to New York for their first official meeting with long-time captain Paul Pierce and former emotional leader Kevin Garnett. About seven weeks later the Garden will welcome their recently-traded stars home. With all the drama and anticipation expected to surround those games during what many anticipate will be a less-than-stellar year there may be none bigger for the Celts all season other than perhaps the return of coach Doc Rivers with his new Clippers. While that last statement may hold true Wednesday brought some news that will at least add an unfortunate wrinkle. The Celtics unveiled their preseason schedule a slate of eight games including two against those very same Nets – Oct. 15 in Brooklyn and Oct. 23 in Boston. What a shame. Teams are responsible for determining their own exhibition schedules (rather than having to adhere to expectations put forth by the league for instance) opening the door for all the blame in the world to be tossed at the C’s and Nets for this calamity. Well except for one problem: The preseason matchups as well as their locations were decided long before the two clubs publicly reinvented their franchises on July 12. “Our preseason schedule for this season was actually set all the way back in last September well in advance of the trade with Brooklyn” revealed Celtics media relations manager Brian Olive in an email. “We are already working on scheduling the games for next preseason.”