Harper's 20 years of service to the Magpies, which ended in July when he joined Hull City, will be honoured by an all-star fixture against AC Milan at St James' Park.
The likes of Alan Shearer, Andy Cole, Les Ferdinand, Faustino Asprilla and Joey Barton will line up for the hosts.
Di Canio is a late addition to the Milan squad, which includes Paolo Maldini, Alessandro Costacurta, Zvonimir Boban and captain Franco Baresi.
All proceeds from the game will be spilt between the Newcastle United Foundation, the Great North Children's Hospital and the Sir Bobby Robson Foundation.
Di Canio's last visit to St James' Park came in April when his Black Cats side won 3-0 in the second Tyne-Wear derby of last season.