The Boston Celtics plummeted a week-worst nine spots to No. 28 in this week's ESPN.com NBA Power Rankings.

Writes curator Marc Stein: "The Celts have lost seven of eight. Four tough games (Nuggets, Clippers, Warriors and Blazers) remain on their five-game swing through the West. Do the math and you're inevitably moved to proclaim that wunderkind coach Brad Stevens' days of flirting with the Atlantic Division lead are a memory."

(Read full Power Rankings)