Newcastle United have conceded 61 goals in the Premier League already this season, the second most in the entire division. They may be struggling to put them in the back of the net at the other end, but allowing their defence to be breached with such regularity means that winning games consistently becomes extremely difficult. Steven Taylor has spent a large portion of the season out injured, Fabricio Coloccini has looked a shadow of his former self and his leadership has been severely wanting, while the less that is said about Mike Williamson's 2014-15 campaign the better. What's concerning is that, aside from Paul Dummett - who has also had fitness issues - Newcastle have the same three centre-backs in their squad that they did during the 2009-10 Championship-winning season. Five years on and the Magpies have made precisely zero progression in this department. Celtic centre-back Virgil van Dijk has issued a "come-and-get-me" plea to Premier League clubs, and Newcastle should certainly be one of the sides interested in his signature. But the reality is that Newcastle need to recruit at least two, probably three, central defenders this summer in order to avoid another relegation battle next season. The board must show ambition and produce the investment they have promised - but who could they bring in? Well, here are 10 centre-backs who Newcastle United should sign this summer.