The only two central defenders that I believe would give us immediate effect in the backline and would hand us a serious chance of winning UCL, would be either Koulibaly or Skriniar.
The both tick all the boxes for me: strong, fast, decisive and reads the game superb, and they played a lot for their respective teams on the highest level.
Then we have the rumours about Unai Nunez, Pau Torres and Ruben Dias.
Nunez future looks very bright and one can see he has a similar playing style to Laporte, coming from the same academy. With his release clause of just 27m, he is definitely worth looking at.
Torres, I don't know much about, but I think he is off the table. Pep is so demanding and throurough about his central defenders, and I think he wants a right-footed partner to Laporte and not another left-footed CB for the build-up play.
Dias has been linked with us for quite some time. He is tall, strong, has good positioning and commanding in the backline which are all great attributes. But looking at the way he plays, he seem to like to lunge in with slide tackles when trying to regain the ball and he ends up on his ass a lot. I think he would give away a lot of freekicks and penalties in the prem. I'm not just convinced when looking at him on YouTube. I have no doubts about his qualities but I'm not sure he is (or will become) the world class CB that we desperately need. For me, the most important attrbutes for a central defender (besides having good feet) are the ability to use speed to close down on attackers when getting countered, intercepting passes and using standing tackles in a decisive manner (like Koulibaly does so well). He is not ticking all the boxes for me.
There is no doubt that we need someone in January. I''m just struggling to see who would be the best fit.