Pirlo was only named the club’s U-23 head coach last month.
But the 41-year-old has now been asked to take over the first team, even before taking charge of a single game.
Pirlo has never managed before either at youth or senior level.
It marks a return to the Bianconeri for Pirlo, who played for the Serie A champions between 2011 and 2015.
During his time in Turin, he won four straight Serie A titles and reached the final of the 2014/2015 Champions League.
His playing career ended in 2017 after a three-year spell at MLS side New York City FC.