Juventus were ruthless as they demolished Parma 4-1 without ever really stepping out of first gear.
Siena, meanwhile, enjoyed a positive return to Italy's top flight after holding Catania to a goalless draw in Sicily.
Siena coach Giuseppe Sannino praised his players for their attitude in that game and believes the same approach will be required against Juve.
He said: "It was a difficult game against Catania, but this team has a great spirit of sacrifice and willingness to fight right now.
"Now we have to produce a similar performance against Juve, a team that will compete for the scudetto this season."
Juventus coach Antonio Conte is set to get a warm reception when he returns to Siena just three months after leaving the club to join the Turin giants.
Conte led Siena to promotion last season and sporting director Giorgio Perinetti said: "Conte is a friend of Siena. He is a talented coach and we were sad to see him leave."
However, Siena will not hand Conte any favours on Sunday.
"We want to beat Juve," Siena striker Emanuel Calaio said. "We know it's going to be difficult because they have many quality players.
"But if we work hard then we can play a great game and perhaps surprise them.
"The fact that we know how Conte wants his teams to play is an advantage for us and we will try to make the most of that."
Conte will be without defender Paolo De Ceglie and injured striker Vincenzo Iaquinta.
Midfielder Claudio Marchisio praised Juve's new coach, who demanded even more from his side despite their comfortable opening win.
"On Sunday, despite the victory, he was angry at the goal we conceded," said Marchisio, a goalscorer in the Parma clash.
"He's conveying quality of play to us, looking to always make us compact and focused. We needed someone who could give us that psychological release and now we should show the results of his work in every game, starting from Sunday.
"It's games like the one against Siena which are important in order to stay at the top end of the table all the way through. They'll be at home, they'll have the crowd behind them and will be aggressive from the start."