Boston Celtics forward Amir Johnson, left, drives for a basket as Denver Nuggets forward Darrell Arthur defends in the first half of Sunday's game in Denver. (AP Photo/David Zalubowski)

Celtics guard Evan Turner, left, works the ball inside as Denver guard Gary Harris defends in the first half. (AP Photo/David Zalubowski)

Celtics guard Isaiah Thomas, center, looks to pass the ball as Nuggets forward Darrell Arthur defends and Celtics forward Amir Johnson breaks for the rim in the first half. (AP Photo/David Zalubowski)

Boston Celtics head coach Brad Stevens, left, argues a call while facing the Denver Nuggets in the first half of an NBA basketball game Sunday, Feb. 21, 2016, in Denver. (AP Photo/David Zalubowski)

Celtics head coach Brad Stevens, left, argues a call in the first half. (AP Photo/David Zalubowski)

Celtics forward Jae Crowder, center, pulls down a rebound between guard Avery Bradley, left, and Denver Nuggets forward Danilo Gallinari, of Italy, in the first half . (AP Photo/David Zalubowski)

Boston Celtics guard Isaiah Thomas reacts after hitting a three-point basket against the Denver Nuggets in the first half Sunday. (AP Photo/David Zalubowski)