Juve leads Lazio by a point ahead of the planned 20 June resumption of the top-flight season in Italy amid the coronavirus pandemic.
The Bianconeri beat Inter in their most recent match on 9 March (AEST), leaving the Nerazzurri — a contender for much of the campaign — nine points adrift with a game in hand.
But Italy coach Mancini has noted the unpredictable results since Germany's Bundesliga returned, with a series of shock away wins in recent weeks.
The former Inter boss believes similar surprises could follow in Serie A, potentially bringing the San Siro side back into the mix, although he thinks Juve's strength in depth makes it the favourite.
"Lazio and Juve will play until the end," Mancini said.
"But since they started playing in the Bundesliga, the home field factor has actually been wiped out. I think that Inter can still have possibilities. In my opinion, there may be some surprises.
"But then it is clear that Juve have an advantage because they have a very large squad."
Mancini is anticipating some struggles as football returns, adding: "All the coaches will have a bit of a problem. The players have come from two months of home training.
"Returning to work on the pitch and resuming playing immediately with competitive games will not be easy.
"The tempo of the matches is much slower. German football does not have the tempo that we are seeing and, in the first games, I think that even in Italy we will not have an extraordinary tempo."