They meet later today in Turin.
"We are the strongest side and proved that over the last three years, but Roma have improved a lot, both in terms of quality and their self-confidence," Bonucci told La Gazzetta dello Sport.
"I expect a very different game to the relatively simple ones we've had against Roma in Turin recently. I do believe it's just Juventus and Roma for the Scudetto. The rest of the group seems pretty far away...
"Francesco Totti is a phenomenon and a real leader, but Gervinho is their key player. He provides the change of pace."
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