It's unclear how long Walker will be out.
Walker has averaged 29.8 points per game over his past six games, and the Hornets were 5-1 during that stretch.
Brian Roberts, who started in place of Walker, had six points on 2-for-12 shooting and four assists in 31 minutes.
With Walker out, the Hornets will be down their top two scorers. Center Al Jefferson has missed eight games because of a groin injury and is still a couple of weeks away from returning.
Along with Walker, third-string point guard Jannero Pargo also is out.
Information from The Associated Press was used in this report.