The striker admits he was amazed by the Colombian's abilities during the brief time together at Monaco and claims a change of coach at the club has made little difference
James joined Real Madrid from Monaco in an €80 million move this summer after impressing during his time in Ligue 1 before lighting up the World Cup.
Berbatov says he knew his former team-mate was bound for a powerhouse club after just a few hours of training with him following his switch to Stade Louis II earlier this year.
"From my first training here, if you understand football, you could see James Rodriguez is a special player," Berbatov said.
"The way he passed the ball, the way he touched the ball. The way he moves on the pitch. You could see the way he was thinking.
"Personally, for me, it was clear that he was going to go to the biggest club. Manchester, Real Madrid, Barcelona, whatever."
Leonardo Jardim's side sit bottom of the French top flight after two losses in as many matches, a far cry from their 2013-14 season - in which they finished second under Claudio Ranieri, and lost only four times for the term.
A 2-1 loss at home to Lorient was followed by a 4-1 thrashing away at Bordeaux but Berbatov insisted his team-mates had worked hard ahead of their trip to unbeaten Nantes on Sunday.
"Obviously it is a bad start. Not the one we expected. The answer is not to worry too much," the Bulgarian said.
"Just keep on working, doing what the coach wants. When the next game comes we need to win. Every team is going to lose, every team is going to win.
"We're going to lose again sometime in the future but I hope it's not going to be on Sunday. We're working hard during the week. Very hard, actually, to correct every mistake we've made in the past two games.
"Hopefully we will do that on Sunday."
Berbatov refused to blame the slow start on the change of coach, claiming players are more than capable of adapting to slight alterations to game style.
"Football is a simple game. Not many things can be different. What difference can it make? You go out there, you play football. One, two touches. Simple," he said.
"You try to win, you try to score more goals than the opposition. There are small things that every coach brings when they go to a new team. Like, you need to press this way or the other way.
"But this is nothing new."