But if Havertz plays for them in the Europa League and suffers a serious injury a la Sane, then his value is gonna drop. Plus, if they want to reinvest the money, you would think they want it ASAP before the transfer window closes.
That is debatable. We had Hazard, who despite his talent, just couldn't be arsed to do his defensive work and led to several managers bemoaned about it.
Even as a squad player, that’s just bad. And you also at least want a reliable squad player, not someone who comes in and could potentially ghosts through games. Remember when Fergie had his Park Ji Sungs, John O Sheas?