As well as Reguilon has done well overall this season, one thing that hasn't been said is that 2019/20 is pretty much his first full, proper season in top flight football. Never mind adapting to the Premier League, we still do not know if he's really the real deal. Lots of players have done well in their first season in top flight football, only to fall off after that. Also, the last few left backs that we have bought from abroad have not turned out too well, despite doing well at their former club - Filipe Luis, Emerson and to an extent Alonso. Maybe the club thought it might be best to go for the safer option in Chilwell - e.g. knowing the league - even if it means spending that a bit more money (that will be offset by a sale anyway). And besides, if we want to get Reguilon and if he continues to do well, we can always go get him considering Alonso will likely be sold at some point, maybe even next summer.