The start of the Zion Williamson era in New Orleans will have to wait. The Pelicans’ No. 1 overall pick will miss a “period of weeks” to start the regular season because of a right knee injury, ESPN’s Adrian Wojnarowski reported on Friday.

It’s not clear how Williamson suffered the injury, but on Thursday the Pelicans announced that Williamson would miss the team’s final preseason game Friday in New York because of right knee soreness. He will remain in New Orleans for testing.

According to ESPN, “a severe injury has been ruled out” and “there’s no shortage of confidence” on Williamson making a full recovery but the team is “clearly treating the injury with an abundance of caution,” Wojnarowski wrote.

Williamson suffered a bruised left knee after only eight minutes of summer league play and was shut down until the team’s training camp. His college coach, Duke’s Mike Krzyzewski, told Forbes that the 6-foot-7, 287-pound forward did not seem to be in shape at the time because of other demands on his time, and said that he shouldn’t have played at all.

“I thought really he never should’ve played just because he’s been on this circuit of awards, the ESPYs, everything,” Krzyzewski said. “I don’t think he’s in the playing shape or the mental shape to play.”

Williamson averaged 23.3 points and 6.5 rebounds while playing 27.3 minutes in the Pelicans’ four preseason games. He received 68 percent of the preseason vote to be named rookie of the year in the NBA’s annual poll of general managers.

The Pelicans open the regular season on Tuesday in Toronto against the defending champion Toronto Raptors. Another NBA rookie — 28-year-old Italian Nicolo Melli — is expected to take Williamson’s spot in the Pelicans’ rotation.

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