Federico Valverde is currently the Real Madrid number 8. The successor to the highly successful Toni Kroos at the number 8 position of RM.
But prior to that Fede was number 15 for a number of seasons. A number he has also been wearing for Uruguay. But prior to that he even more yet another number though very shortly, which was the number 27. He might never have played an official match with the number 27 but he was inscribed with number 27 initially prior to the 18/19 season. Then later on he made the switch from 27 and to 15. A bit similar to Gavi with Barcelona who started at 30 then move to number 6.
The La Liga outfit looks like this from the side.
The La Liga badge shown in the photo was replaced by a new design for the season 23/24.