"After careful thought and consideration, I’ve decided I will not be participating in this year’s NBA All-Star competitions," Davis said in a statement on the team website. "I want to thank the fans for voting me into the All-Star game and I am sorry I will not be able to play."
Davis, in his third NBA season, is fourth in the league in scoring (24.5) and first in blocked shots (2.74). He averages 10.3 rebounds and has 29 double-doubles.
The 36-year-old Nowitzki is averaging 18.3 points and 5.9 rebounds and will be making his 13th appearance in the All-Star game.
Portland Trail Blazers guard Damian Lillard and Sacramento Kings center DeMarcus Cousins previously were named Western Conference replacements for the game and Atlanta Hawks forward Kyle Korver was named an Eastern Conference sub Tuesday.
Davis has missed seven games this season because of injury.
"More than anything, I am anxious to get healthy and back on the court with my teammates after the All-Star break," Davis said.
Follow Matt Wilhalme on Twitter @mattwilhalme