The German defender feels his former team-mate has every chance of winning the individual award this year and has hailed his professionalism
The Madrid attacker had to settle for second spot in the prestigious individual award in 2011 and 2012, but his former team-mate believes he could very well bring home the trophy the next time around.
"I believe that Cristiano Ronaldo - and not Messi - can win the Fifa Ballon d'Or if Real Madrid win the Champions League this season," Metzelder was quoted as saying by Bild.
"Cristiano is probably even more complete than Messi because of his incredible dynamics. A shot from 45 yards out is like a rocket with him."
Metzelder played alongside Cristiano Ronaldo at Madrid in 2009-10 and the centre-back has fond memories of the Portugal international.
The German added: "He might seem arrogant to the public, but I got to know him as a real friend. His life is all about football. He's not interested in visiting clubs and bars."
The prolific attacker has been in sublime form in 2012-13, netting 31 goals in 30 Liga appearances.