The only reason I'm somewhat interested in this is because he's right-footed and can play full-back on both sides of the pitch. If he's good then he can probably displace AWB as the secondary right back option, and be real competition for Dalot, whilst also get minutes at left back if last season's injury woes continue there.
However, if he was being brought in exclusively as a new left back, then I'd much rather take someone like Reguilón who would almost be free as a decent back-up option. We have 3 good left backs already (Shaw, Malacia, Martínez) + Amass is turning 18 next season. I'm not willing to give up on any of them just based on last season. Spending big money on a left-back this summer would be silly IMO. First of all, a few long-term injuries in the case of Martínez and Malacia don't equal injury proneness. Secondly, if Shaw is managed carefully, he can still play 30+ games in a season. Thirdly, I trust in Ineos solving our injury situation, because I don't believe it was all just bad luck last season.