Celtics become first team to clinch spot in NBA playoffs

BOSTON — There is still a month left in the regular season, but the Boston Celtics have already locked up their spot in the playoffs. Boston became the first team in the NBA to clinch a spot in the postseason on Thursday night. This has been a forgone conclusion for a while, as Boston has pretty much rolled through the regular season. The Celtics improved to an NBA-best 52-14 on the season with a win over the Phoenix Suns on Thursday night, and then clinched their spot in the playoffs with a Philadelphia 76ers loss to the Milwaukee Bucks. Boston remains 9.5 games up on Milwaukee in the East, and should clinch the No. 1 seed in the Eastern Conference…