Del Neri reminded players not to get too carried away with making promises of winning the Scudetto.
His comments come less than 24 hours after captain Alessandro Del Piero claimed he wanted to win an important trophy. Despite demands, the overall outlook is good.
"We have been working well, but there is still plenty of work to do seeing that the international players are yet to return, in any case we are happy with the physical improvements," he told Sky Sport Italia.
"I expected the players to show will and they have. There is quality here, but also plenty of effort."
Diego claimed he wanted to stitch together his own rescue plan as he seeks a better future at the club, and Del Neri responded.
"Diego? He can play in a support role for the strikers. I think this is his role," he said.