Chiellini suffered a calf injury and was substituted in the first half of Wednesday's match, although Allegri was confident afterwards it was not a serious issue.
And so it has proven, with the Bianconeri coach able to tell a news conference on Friday the captain should be back in "10 to 15 days".
Allegri revealed that Martin Caceres - who returned for a third spell at the club this week - is in line to start in Chiellini's absence against Parma on Saturday, while Mario Mandzukic is back in attack.
"The lads have trained well," Allegri said. "Chiellini's injury is not serious – he should be back in 10 to 15 days.
"Mandzukic will return up front and I have to decide who else will play alongside him and [Cristiano] Ronaldo – it will be either [Paulo] Dybala, [Federico] Bernardeschi or Douglas Costa.
"Caceres will partner [Daniele] Rugani at centre-back, [Mattia] Perin will start in goal and [Leonardo] Spinazzola or Alex Sandro will play at left-back – Spinazzola has a good chance of starting. [Miralem] Pjanic is ready in midfield.
"The main thing is we bounce straight back after losing to Atalanta. We still have lots of games to win if we want to reclaim the Scudetto and we must keep Napoli at a safe distance."
Juve's defensive issues - with Leonardo Bonucci also out with an ankle injury and Medhi Benatia having departed - prompted deadline-day talk of a move for Parma's veteran centre-back Bruno Alves.
But Parma dismissed the speculation at the time and the Portuguese signed a new contract on Friday to keep him at the club until June 2020.
"I want to thank Parma for their faith in me," said the club captain. "I feel at home here and I'm happy to be part of this family."