The three outside of Bruno & Maguire is pretty obvious — Casemiro, Varane and Martinez. Varane is more of a calming influence (although he has some fire in him — watch him trying to make our players acknowledge the fans at Anfield straight after the game instead of immediately sneaking into the dressing room) while Casemiro and especially Martinez are extremely vocal and aggressive — it really depends on what type of captain do you prefer to have.
De Gea sometimes appears in these discussions due to the length of his stay but let's be honest, if he had any leadership qualities, he would've
- been made a captain already
- been able to organize his defense — if you can't deal with 4-5 players, how are you supposed to deal with the entire squad?
But let's be honest — Bruno will be a captain or one of vice-captains at worst, despite the understandable criticism. He's very vocal, his work-rate and attitude is spot on 95% of the time (him switching off against Liverpool really isn't something that he does regularly), he's always there and he's very popular in the squad.