At least 2, and we need to be looking to improve as well. Better organising under new management would help also, but we need as much competition as possible as well. The goals against tells its own story. Robertson has had problems, others aren't proven, Elmo often looks weak, Davies has been way off form.
Silva prefers two central defenders, we've currently got three with another due back in a month, so I'm not sure it's a priority. The right back obviously is.
That's what I'm thinking. We have 4 cb's for two positions. Once/if a RB is signed, I think the defence is set.