Comparing the Argentina captain with Arjen Robben of the Netherlands and Brazil's Neymar, Sabella on Tuesday held up Messi as the undisputed No. 1.
"Robben is a great player. He is very important for Holland. Like Neymar is for Brazil and Messi for Argentina," Sabella said. "Each of them is important for their teams, but Messi is the best of them all."
After a disappointing World Cup four years ago, Messi has carried Argentina into the semifinals in Brazil, scoring four goals -- the same tally Neymar reached before injury ruled him out of the tournament. Robben, who faces Argentina in the second semifinal on Wednesday, has scored three.
Though he's been named world player of the year for times for his accomplishments with Barcelona, Messi hasn't had the same kind of success with Argentina, who haven't won a major title since the 1993 Copa America.
This is the first time since 1990 that Argentina have reached a World Cup semifinal, which Sabella said was a victory in itself.
"After 24 years Argentina is among the four best teams in the world," Sabella said. "I think this group of players has already won. Let's see if we can win even more."
If they do win the semifinal, Argentina won't have to worry about rivals Brazil in the title game. Sabella was just as stunned as everyone else to see Brazil lose 7-1 to Germany in the first semifinal, a game Argentina's players watched the end of on TV at Itaquerao Stadium, even delaying their training session for around 20 minutes.
Sabella said the heavy defeat for Brazil was clearly "not normal."
"But in football you have to expect these things," Sabella said. "It's football. It's the most illogical of sports. Things happen that you cannot foresee."
Sabella 7-1 is not a normal result
Argentina coach Alejandro Sabella comments on the match between Brazil and Germany
Sabella: Di Maria plays well with Messi
Argentina coach Alejandro Sabella comments on the impact the team will have by not having Angel Di Maria in the lineup.