They do need a defensive midfielder, but personally I think they look strong apart from that, just need time for new players to bed in. The two midfielders they have signed are better than the ones have left, get a decent defensive midfielder in and they are right back in the mix.
I think the biggest reason they have dropped off isnt the midfield, isnt losing two fantastic attackig players.....it is actually the defence. And its simply that individually the defenders are good but nowehere near as good as made out to be.....and thats because for a good 18-24months those players massively over performed. Van Dijk was a massive transfer and he was the best defender probably in the world for a good while.....when in rality, he is just a good defender, isnt even top 10. Robertson was arguably the best left back in the world....again he is just a good left back. Alexander Arnold was touted as one of the best players in the world.....and he cant actualyl defend. I couldnt believe how wewll they played as a unit for a fair while, thought i misjudged the first two as signings....I think they are playing nearer there real level now....but they are still good players, they just arent among the very best in the world, I still think they will be right up there for top 4 come the end of the season though, jstu not challenging CIty like the last few years....as the defenders wont over perform for so long again