Arsenal are in talks to sign Ligue 1 centre-back William Saliba and are chasing Celtic full-back Kieran Tierney.
Unai Emery desires to herald a centre-back, however Nicholas warned Emery he needs a couple of.
‘Two centre-backs, immediately,’ Nicholas informed the Transfer Talk podcast..
‘Immediately two centre-backs. They need a bit of pace, they’ve by no means actually had the tempo.
‘The man who had tempo was (Laurent) Koscielny, however he sort of misplaced his tempo two, three seasons in the past underneath Arsene Wenger.
‘It was through the injuries, it wasn’t the lad’s fault, nevertheless it was the fact of the accidents has caught up with him..
‘Then after that we had to go round about the houses to accept that (Shkodran) Mustafi didn’t slot in. Sokratis, for my part, is a powerful defender, however he performs solo.
‘And Arsenal underneath Unai Emery have to be a unit, they’ve to get the defensive construction proper.
‘(Nacho) Monreal has truly finished okay for Arsenal contemplating what his limitations have been..
‘He was a left-back, he was by no means a centre-back however he had to play there.
‘That always told me the reality was that Arsenal’s massive, massive issues is centre-backs and so they want two centre-backs for my part.
‘A left-back like (Kieran) Tierney would be absolutely welcome, (Hector) Bellerin is probably still a bit away from fitness, we don’t have sufficient cowl in there.’