Some Milan fans called on the Italian premier to sell up after seeing their best player Kaka join Real Madrid in the close season with the only major buy being Dutch forward Klaas-Jan Huntelaar moving in the opposite direction.
Saturday's impressive 2-1 win at Siena on the opening day gave credence to Berlusconi's argument that there was no need to splash out when the club already had plenty of big names looking to prove their worth after two disappointing seasons.
Ronaldinho responded to Berlusconi's calls to show he could make up for Kaka's loss by inspiring both of the goals scored by his 19-year-old Brazilian compatriot Alexandre Pato.
"We have a 29-member squad. We can field two quality teams with champions others can only envy us," Berlusconi said on Italian television this week. "I wouldn't swap Ronaldinho with anyone I know, even though he is 29".
One area of concern before the season was that the signing of American defender Oguchi Onyewu, who came as a free agent from Standard Liege, was not enough to reinforce a back-line weakened by captain Paolo Maldini's retirement.
"He's a great player. Together we can form a really good partnership," Nesta told the club's in-house TV channel.
"It was a good performance and a good result but we have to be consistent," he said. "We're just at the beginning."
In the weekend's other big game, Juventus, who started their league campaign with a 1-0 win over Chievo Verona, on Sunday visit AS Roma, who lost 3-2 at Genoa.
