The Spain international has praised the Barcelona star and rates him over Madrid attacker Cristiano Ronaldo.
The 26-year-old has won four consecutive Ballons d'Or awards and Guti has stressed that the prolific attacker always delivers the goods when his team needs him.
"I can only repeat what I have already said before and that is that Messi is the best in the world at the moment. It pains me to admit it, but it's the simple truth," Guti told Punto Pelota. "I am not saying that Messi is on another level than Cristiano, though. But he's more decisive at certain moments when the team really needs him. He can salvage a game by himself.
"They are arguably the two best players in the world, but when it comes to my personal preference I must admit that I like Messi more."
Messi has netted over 200 goals for Barcelona in La Liga since breaking into the first team in 2004-05.