He's evidently a very good defender & is pretty accomplished with the ball at his feet, but I still think Left Back is a position I'd prefer a specialist player at.
We bought Gomez as a converted midfielder to fulfil that role. Reports suggest there's firm interest in him this window & he wanted to explore a move whether on loan or permanently, but Pep persuaded him to remain.
Does Pep see Sergio as a long-term solution to our LB conundrum? He's another player (like Philips) where it's painful seeing him sat on the bench getting splinters in his arse, game after game.