The Boston Celtics are expected to be championship contenders this season, but have lost 11 of their last 26 games

"There's no doubt they're vulnerable," Legler said. "They're vulnerable for a variety of reasons. One, it's how good Cleveland is, like they're legitimately a team that is going to give Boston fits if they play eventually in the conference finals,

Boston has been inconsistent for weeks — a stark difference from last season’s joyride — but is still among the best defending NBA champions of this century.