Dias, like Cancelo, is better on the left side. Maybe it's something in Portugal that makes a right footer more comfortable on the left side - I don't know! Stones is better at RCB than Dias. Stones and Dias is clearly our best partnership as shown by how solid we were advancing to last year's final.
Laporte comes back in and the defensive capitulations come back in. Losing Walker makes a difference of course. Fully fit and under pressure he has the ability to drive into space and get us up the other end of the pitch. But Laporte has been directly at fault for a number of goals we've conceded in our CL exits.
We should be looking to replace him with someone quick, even if they're not consistently amazing defensively. It would make so much difference dealing with the counter to have someone who can win a foot race.