The Sweden international, who played alongside Messi during his season-long stay at Barcelona in 2009-10, is of the opinion that while Ronaldo is a wonderful player, he has had to work hard to get where he is today.
"Leo Messi is all talent, while Cristiano Ronaldo is the product of much training," Ibrahimovic told TV3.
However, the AC Milan striker suggested that Ronaldo is probably the more complete player, arguing ahead of the Rossoneri's Champions League meeting with Messi's Barcelona at Camp Nou that the three-time Ballon d'Or winner is somewhat one-footed.
"Messi does not need his right foot, though," Ibrahimovic conceded. "He only uses the left and he's still the best in the world!
"Imagine if he also used his right foot ... Then we [Milan] would have serious problems!"
Milan's eagerly-awaited quarter-final second-leg clash with the Blaugrana gets underway at 20.45CET on Tuesday.
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