However, Calafiori's preference for working under Mikel Arteta in the Premier League led him to choose Arsenal over other English suitors like Chelsea and Tottenham.
The transfer has also sparked a financial dispute involving three clubs. Bologna's sale triggers a complex sell-on clause with Basel, Calafiori's former club, entitling them to 50% of the transfer profit. Roma, Calafiori's youth club, also claims a 40% stake in Basel's share.
Despite the financial wrangling, Calafiori is expected to complete his move to Arsenal this week, having agreed to a five-year contract. His arrival is seen as a major coup for Arsenal, strengthening their defensive options with a promising talent.
He currently earns around EUR14.2k per week (EUR740,000) in Italy, a salary that is not much more than what reserve goalkeeper Karl Hein earns at Arsenal.
So, Calafiori will see his wages rise significantly with reports from Italy claiming he will earn EUR4m-a-year after tax.
That's EUR80k-per-week for those who prefer that breakdown, a rise of 563% on his current salary.
That would put him above Jakub Kiwor (EUR58k-per-week) but well below Jurrien Timber and Leandro Trossard, who both earn EUR90k-per-week.
At Arsenal, the 33 was last used by young goalkeeper Arthur Okonkwo, who held it since the 21/22 season. As he has departed permanently to join Wrexham FC, that number is now free.
Should Calafiori feel like a change, Kieran Tierney's 3 is likely to be available with the club showing no issue when it comes to taking numbers from players who don't have a future in the first team.
Beyond that, there are no first XI numbers available with 13 the next free number. Last worn by Runar Alex Runarsson, it is usually reserved for the second-choice keeper at the club. With Aaron Ramsdale using the number 1, but possibly on his way out, we could see David Raya swap his 22 for the 1, leaving 13 to be taken by the senior keeper Arsenal are still trying to sign.
16 (Rob Holding), 17 (Cedric Soares), 23 (Albert Sambi Lokonga), and 25 (Mohamed Elneny) are the other free numbers in the first 25.