Despite the disappointment of bowing out in the semi-finals of the Club World Cup, the striker is confident his veteran team-mate could opt to sign a new deal with the club
The Copa Libertadores champions suffered a surprise semi-final exit to hosts Raja Casablanca before going on to edge the third-place playoff 3-2 against Guangzhou Evergrande.
Despite admitting defeat was a blow, Tardelli feels the chance to defend their Libertadores crown will provide enough incentive for the club's stars - including Ronaldinho - to stay.
"I do not know [if Ronaldinho will sign a contract extension], so we talked and I believe that he will, yes," the 28-year-old told reporters.
"We have to play to erase the shame from the Club World Cup, which will take a while to forget, but we need to start with the right foot and play the Libertadores in the same way we did this year.
"Hopefully everybody that helped us win the Libertadores [in 2013] stays."
Ronaldinho scored and was sent off in the win over Marcello Lippi's side in Marrakesh.