Why did the Boston Celtics' 2018-19 go off the rails? Here's the prevailing theory: Kyrie Irving and Gordon Hayward, who both missed the 2017-18 playoffs, struggled to assimilate into a roster that reached Game 7 of the Eastern Conference Finals without them, creating deep chemistry issues on a roster supposedly brimming with talent. According to Bleacher Report's Ric Bucher, executives around the league apparently buy that theory, but more specifically believe the contract structure of the Celtics' most important players also played a role in their demise.