It's a weird one as he has played badly in long patches and brilliantly in long patches, played great in some big games but looked a bit lost for the Portugal NT at times. I think he's a bit of a confidence player tbh as different managers have manager to get vastly different performances out of him. Personally, I've always thought he was more suited to managers who let him express himself a bit more as that's when he's at his best, as a pure holding midfielder he's a bit wasted. It's a tough one as he clearly has all the attributes and is capable of being the perfect player for us, but he's been inconsistent so it would be a gamble.
We definitely need someone with that blend of physicality, defensive solidity and controlling passing ability though and there aren't many about. Not seen enough of NZonzi this year to know what his passing it like but I remember him definitely ticking the physical boxes, he'd struggle to stay on the pitch playing for us if he's still anything like he was as Blackburn and Stoke!