The 20-year-old striker was surprisingly dropped for last weekend's meeting with Napoli at San Siro but he will be recalled for the trip to Turin to face the Bianconeri
The 20-year-old was surprisingly dropped for last weekend's equally important meeting with second-placed Napoli, with Allegri explaining after the game that the Rossoneri's top scorer was emotionally and physically drained.
However, the former Cagliari boss has now revealed that the 20-year-old striker will be restored to the starting line-up for the trip to Turin.
"He will play tomorrow," Allegri told reporters during his pre-game press conference.
"I repeat that it was a tactical decision [to leave him on the bench against Napoli]. Stephan is having a year of great intensity and big numbers and a benching doesn't change my assessment of the player.
"If Balotelli had been there, maybe his exclusion would have caused less controversy, but he was replaced by a player of the quality of Robinho.
"It was a decision made by the coach, but Stephan remains an integral part of Milan, and indeed Italian football."
El Shaarawy's omission sparked speculation over not only the player's future at San Siro but also that of the coach. However, Allegri insists that he wants to remain with the Rossoneri.
"At this moment, there is no news," he insisted. "I am at Milan, and I hope to stay here.
"I am attached to the president [Silvio Berlusconi] and [CEO Adriano] Galliani. I hope to stay here for a long time but now we should be thinking only of Juve, then Catania and, from week the week, our Champions League objective.
"When you think of the difficulty we experienced at the start of the season, and the great reconstruction undertaken with great credit to Berlusconi and Galliani, this group has a great future ahead of them."
For the moment, though, Allegri is solely focused on upsetting Juve in their own backyard.
"I have all the guys available," he revealed. "I have got [Ignazio] Abate and [Kevin-Prince] Boateng back.
"But it will not be an easy game against Juve. "They always play the game with great aggression and great organisation.
"They are looking to secure the points that would seal first place in the championship, while we need to points to hold onto third place and remain on the heels of Napoli.
"There are only six games remaining in the battle for the top three places."
Milan currently set third in the Serie A standings, four points behind Napoli and a further 11 adrift of leaders Juve.