In an interview with AFP on Monday ahead of his induction into the FIBA Hall of Fame, Nowitzki said he was stunned by the impact the 22-year-old French player was having on the game.
"I mean, he's changing the game as we speak. I've never seen anything like it," the 2007 NBA MVP said.
"His defense is so good that he changes the game just by being on the court and taking away some of the layups and twos that other teams would usually take."
Wembanyama scored 35 points, the most on a playoff debut in franchise history, to go with five rebounds and two blocks as his San Antonio Spurs beat the Portland Trail Blazers in round one of the playoffs.
Playing just his third NBA season, the forward/centre is in the running for MVP and Defensive Player of the Year honours.
The 2011 NBA champion said Wembanyama had the otherworldly ability to help the young Spurs overcome their lack of experience.
"They're definitely ready. They're definitely there. Of course, the one question about the Spurs is 'are they experienced enough?'
"But I think Wemby is kind of that x-factor that takes that away. He levels that whole experience thing out."
Nowitzki, 47, said the Spurs could get past defending champions Oklahoma City Thunder and reigning MVP Shai Gilgeous-Alexander.
Should the Spurs get past Portland and either the Denver Nuggets or the Minnesota Timberwolves in the next round, they are on track to meet the Thunder in the Western Conference Finals.
But the first-ever unanimous 2025-2026 Defensive Player of the Year, who also became the youngest ever to win the award, could be the one to get it done.
"They'll definitely think that they can. They're a tough matchup for OKC.
"We've seen that. They beat them, like, three times around Christmas.
"They have all the guards and can attack them. So I don't know if it's a year or two too early. We shall see.
"It's going to be a fun playoff run. So they're definitely knocking on the door."
A skillful European big man who could shoot, Nowitzki was a pioneer for players like Wembanyama, but said he had plenty to learn from the young Frenchman.
"You watch a game, you keep watching Wemby, and I'm like 'man, that's a cool move'... Let's go in the gym tomorrow and work on that."
"Learning the fundamentals of the game is a journey that keeps on going."
