Several years ago, I had to deal with a cabal of six employees who thought they were above the law at our company.
A staff meeting was called where the three "Locker Room Lawyers" were sacked, & their three sycophants were given final written warnings. Two of the sacked were crucial to the business, but I reasoned their toxic presence was more damaging than losing their specialist technical skills.
Best move I ever made. Order was restored & the three on final warnings actually went on to become future star employees & senior management, after stepping up to the plate to replace their former colleagues.
Squad unity & discipline is far more important than ANY player. If Cancelo isn't being picked because of his poor attitude anyway, all we lose is the option to pick him when needed, with zero guarantee of how he'd perform when/if called. If we keep him, what would be the cost to the overall squad?
As for a replacement? It wouldn't surprise me if we brought in an experienced LB on loan. Then again, it wouldn't surprise me if we didn't. Regardless, in Pep/City do I trust.