The 25-year-old's future remains the subject of speculation as he continues to struggle to secure a regular starting spot under Zinedine Zidane.
James suggested at the Club World Cup in December that he could look to leave in the January transfer window, but he will reportedly hold talks with the Madrid hierarchy on his future at the end of the season after no move materialised last month.
But Rincon, who spent a season at the Santiago Bernabeu, has suggested that James may benefit from playing away from the Spanish capital until he has developed a mentality to become a star at a major club.
"James is a very technical player, a very important one, but he needs more dedication in order to be a great star," the 50-year-old told Marca.
"Right now, he doesn't have the personality to lead a team like Madrid."
Rincon, who also had a short spell at Napolo, believes it will be a tough encounter but has tipped Madrid to triumph.
"I played with both teams and I'm glad that Napoli are competing at this stage," he said. "I don't think that it is going to be an easy match at all for Madrid because Napoli play very good football.
"Both teams treated me very well when I played for them but if I had to bet, then I'd be betting on Rodriguez's side."
Rincon identified Luka Modric, Dries Mertens and Marek Hamsik as the three potentially decisive players in the tie, although he was most effusive in his praise for centre-back Sergio Ramos.
"Modric has an exciting quality and Ramos is without a doubt the best centre-back in the world," he added. "Mertens has evolved a lot - it's lucky that he's at Napoli. Hamsik is also very important."