For me Maguire is a good defender, but never an elite one. I thought he was the wrong signing and even with premiership fees at a ridiculous price.
He has been dreadful so far this season, no doubting that, but I think the over reaction from that of people labelling the worst player etc etc is excessive, he was decent towards the end of last season, we did actually muss him in the Europa final for example.
I dont think he needs replacing but he does need serious competition to partner Varane which I dont think is there at the moment. JOnes obviously needs to go, Tuanzabe should be going too. Bailly for me all round is actually the next best defender BUT the constant injuries and still making rash decisions, he isnt the answer. I think all three of them should be moved on this summer personally as none provide consistent reliable cover or competition. The only other one is Lindelof, and he has actually improved this season, enough to remain in the squad, but a starting eleven player for a side challenging for titles....get out of here. He is still no more than decent, weak in the air, weak on one on ones, weak defending through balls and crosses, competant but nothing special like some make out on the ball.
I think we should keep Varane, Lindelof and Maguire but provide competition for all of them. An experienced free like Romagnoli and a reasonably priced hot youngster of which a few names are getting mentioned would be good this summer.
As someone else mentions a bit higher in this thread, of more importance though is improving our central midfield. It is hard to judge all of the defenders when at the moment they are so often over exposed. Better protection in front of them and player that are able to cycle the ball better so not so many passed back to them would be as beneficial as and centre back signing