"Dybala is available, he's well, he's done two training sessions with the squad so he'll be available," Allegri told reporters.
"We've almost got a fully-fit squad, which is important because we have quite a few matches between now and the next international break (November 8-19)."
Around 56,000 fans are expected at the San Siro as Inter host their first big match since maximum stadium capacities were increased to 75 percent by the Italian government earlier this month.
Juve sit seventh, three points behind third-placed Inter after a run of four straight league wins in which they have impressed more for their doggedness than for their play.
They are however still 10 points behind league leaders Napoli, who have won all eight of their matches and face Roma in the Italian capital just before Sunday's big match in Milan.
Champions Inter fell to defeat at Lazio last time out after a second-half meltdown over refereeing decisions but looked strong in their 3-1 Champions League win over Sheriff Tiraspol midweek.
"Inter are still favourites for the league title so tomorrow will be test against a good team," said Allegri.
"Tomorrow isn't a decisive game in my opinion. Tomorrow is a chance to take a step forward and continue our positive run of results, but it's not a decisive match."