The Argentine captain helped his side to victory in World Cup qualifying on Saturday, after curling in a free-kick during his nation's 3-1 win over Paraguay in Cordoba.
And Seballa explained to Marca how the diminutive forward is now in high spirits.
"Messi is happy," the Argentine boss is quoted as saying. "He's on the top of his game and he's showing it out on the pitch. When he's in that sort of mood and feeling happy, we have a great chance of him giving us many more happy moments."
Seballa's words come after Messi himself had gushed about his current state within the national camp.
"This is a beautiful feeling. It's amazing when the crowd shows you so much love. It has happened in the Copa America, here in Cordoba, and in Buenos Aires, too," said Messi.
Messi, who has now scored 10 goals in his last 6 games with Argentina, has helped to lead his country to the current top of the CONMEBOL 2014 World Cup Qualifying table.
Perhaps more importantly for Argentina supporters,the Rosario-born magician appears to be in the right frame of mind heading into a crucial tie with Peru on Tuesday in Lima.