The 19-year-old is believed to have a bright future ahead of him at the Parc des Princes but at present he is down the pecking order under manager Unai Emery.
In a bid to get more first-team experience under his belt, PSG have decided they will allow the playmaker to make the switch to Palermo, who are currently pushing for a return to the Italian top flight.
Callegari does have Italian roots but was born in France and has featured at youth level for the French national side.
Michy Batshuayi's cheeky backheel was enough to give Borussia Dortmund a 1-0 win over Hannover 96 at Signal Iduna Park on Sunday, lifting them within a point of second-placed Schalke.
Eintracht Frankfurt boss Niko Kovac felt his side could have scored more goals following their 3-0 defeat of Mainz on Saturday.
West Brom manager Alan Pardew refused to fault his players' efforts after a heartbreaking 2-1 loss to Bournemouth that dashed their already slim survival odds.