Squad numbers FFS mean nothingFor context, they didn't have anyone in the 4 or 25 shirts last season either: https://www.90min.com/posts/chelsea...23-squad-numbers-including-sterling-koulibaly
Edit: Badiashile took the 4 when he joined, but this season has switched to 5, which he wore at AS Monaco: https://www.transfermarkt.co.uk/benoit-badiashile/rueckennummern/spieler/463603 (Jorghino was in 5 last season, until he moved to Arsenal)