The former Madrid star feels Barca are still on a higher level, and stated that the biggest difference between Messi and CR7 is their performances in key matches
Ronaldo smashed La Liga's goals record last season, netting on 40 occasions, but was unable to help the Santiago Bernabeu side to the league title or to Champions League glory.
"He is a great player and has been decisive in many games. However, what happens in the big games is that he fails to deliver the goods - something that Lionel Messi did for Barcelona. The real stars are those players who shine at the big moments," Guti said to Punto Pelota.
The Besiktas playmaker added that Barcelona remain ahead of rivals Madrid, and expressed his disappointment with the lack of homegrown players in Jose Mourinho's line-up.
He added: "Madrid have not yet reached the level of Barcelona. It will be very hard to beat them if you line up all players against each other one-by-one. My biggest sadness is that Iker Casillas is the only youth product in the team. We spent some money on new signings, rather than in youth investment."
Guti is a product of the Real Madrid youth academy and made over 500 appearances for the capital giants, before leaving them to move to Turkey in 2010.