Justin Kluivert will wear shirt number 34 for Roma in tribute to his former Ajax team-mate Abdelhak Nouri.
The Netherlands international completed his switch to the Serie A side from Ajax for €17.25 million (£15m/$20m) in June.
And Kluivert announced on Saturday he will honour Nouri in his choice of shirt number at Roma.
"Why 34? Appie's number," Kluivert wrote on social media.
"My prayers and shirt number for you, my friend-brother who taught me so much."
Managing director Edwin van der Sar said: "We recognise our responsibility and liability for the consequences of this."
Kluivert has now honoured a close friend that he worked alongside while part of a famed academy system in Amsterdam.