The Barcelona star had only previously scored one goal in tournament finals history, but has netted four times in just three games in Brazil so far, with a round of 16 clash with Switzerland on Tuesday up next.
And Sabella insists that it is a return to form that, he, Messi himself, and the rest of Argentina had seen coming.
“Messi is playing an amazing World Cup, as everyone expected. He expected it, his colleagues expected it and all Argentines expected it,” Sabella told a press conference on Monday.
Parallels have been drawn between the influence of Messi on Argentina and his Barcelona colleague Neymar’s effect on Brazil, while the legacy left by Diego Maradona in leading the Albiceleste to glory in 1986 also draws comparisons.
But Sabella insists it is natural for successful teams to be built around such outstanding talents.
“I think both Messi and Neymar are amazing players. Messi is the best in the world and Neymar is a great player, and with players like those it’s normal that teams depend on them.
“Maradona was a very important player to the team in 1986 and Messi is very important to us now.”
After winning three games from three in Group F, Argentina take on Ottmar Hitzfeld’s Swiss outfit in the last 16, and the 59-year-old coach says it is now the time for his team to ramp up their form.
“We’re improving. The last match [against Nigeria] deserved a mark of seven [out of 10], since I know you like ratings. But maths is not everything.
“The team is very spirited. We’re all positive, but it’s true this is a different phase and mistakes are not acceptable.
“You can make mistakes in the first phase, but we know we have to keep focused and stay balanced. There are two reasons for that. We cannot go back, and mistakes are not acceptable at this stage.”
The clash at Arena Corinthians kicks off at 18:00CET on Tuesday.