Reigning champion Djokovic overcame Stefanos Tsitsipas in a three-set epic on Saturday to set up a meeting with Rune, after he stormed into his first ATP Masters 1000 title clash with a comfortable win over Felix Auger-Aliassime.
A victory for Rune will ensure that he breaks into the top 10 for the first time but Djokovic, who beat the Dane in their meeting at last year's US Open, hoped to delay his young friend's first Masters 1000 crown.
"We get along really well. Good friends off the court. Of course on the court, competitors. I played him only once...good battle, four sets. He has improved a lot. Physically, he's a fit guy. He's young so not much to lose," Djokovic told reporters.
"I expect that (on Sunday)...He reminds me of myself, solid backhand, very good defence and just competitive...every point leaving his heart and his legs out there on the court. It's nice to see. I think he's very good for our sport in general."
Djokovic, who is gunning for a seventh Paris Masters crown, said Rune deserved all his success having reached four straight finals during the indoor season.
"I've followed him the last three-four years, his uprising through Challenger level and then getting now to top 15 in the world," Djokovic said.
"No doubt he's the future of the sport along with Carlos Alcaraz and some other guys."
