I'd say we definitely need a top tier mid to replace Ramsey because... well... we don't have any top tier midfielders right now.
As much as I'd love to sign Locatelli, we can't put that burden on him. But we could debate on the definition of 'top tier'. Doesn't necessarily need to be an expensive operation like Pogba.
Ramsey now is not our starting mid
Maybe the top tier you mean is rabiot replacement
Mckennie is a box to box who occasionally advance in box area
If u really mean ramsey replacement than we have to bench mckennie
Mckennie isn't optimal in double pivot that arthur and bentancur play now.
If he play double pivot and we force him to advance more to the box, it will be the same as our games before supercoppa when there were big hole to be exposed in our mid for opponent to launch deadly counter.
Of course pirlo 's tactic can change. But as long as we deliver with current tactic, why would we change then?