Dirk Nowitzki #41 of the Dallas Mavericks covers Trevor Ariza #1 of the Houston Rockets in the first half at American Airlines Center on January 24, 2018 in Dallas, Texas.

James Harden #13 of the Houston Rockets reacts after scoring against the Dallas Mavericks at American Airlines Center on January 24, 2018 in Dallas, Texas.

Dirk Nowitzki #41 of the Dallas Mavericks shoots the ball against James Harden #13 of the Houston Rockets in the first half at American Airlines Center on January 24, 2018 in Dallas, Texas.

Referee Bill Kennedy looks on during the game between the Houston Rockets and the Dallas Mavericks on January 24, 2018 at the American Airlines Center in Dallas, Texas.

Referee Bill Kennedy makes a call during the game between the Houston Rockets and the Dallas Mavericks on January 24, 2018 at the American Airlines Center in Dallas, Texas.

Referee Michael Smith warms up before the game between the Houston Rockets and the Dallas Mavericks on January 24, 2018 at the American Airlines Center in Dallas, Texas.

The sneakers of Gerald Green #14 of the Houston Rockets during the game against the Dallas Mavericks on January 24, 2018 at the American Airlines Center in Dallas, Texas.

The sneakers of Gerald Green #14 of the Houston Rockets during the game against the Dallas Mavericks on January 24, 2018 at the American Airlines Center in Dallas, Texas.

The sneakers of PJ Tucker #4 of the Houston Rockets during the game against the Dallas Mavericks on January 24, 2018 at the American Airlines Center in Dallas, Texas.