Manchester City are set to make a splash in the transfer market and defence is the area in the spotlight. City struggled defensively in the absence of injured star Aymeric Laporte following Vincent Kompany's exit, while there are doubts over John Stones' future in Manchester. Napoli's Kalidou Koulibaly and Bournemouth defender Nathan Ake are reportedly high on Pep Guardiola's wish list as he attempts to strengthen his squad after watching Liverpool coast to the Premier League title. Manchester City have informed Napoli they are ready to make an offer for star defender Kalidou Koulibaly, according to Sky Sport Italia. Pep Guardiola has set his sights on Koulibaly, who has also been linked to the likes of Liverpool, Manchester United, Real Madrid and Paris Saint-Germain. City are willing to bid €65million (£58m) but Napoli are still holding out for €100m (£90m).