Kalidou Koulibaly ahead of the summer window.The Senegalese central defender continues to be linked with a move away from Naples at the end of the season and Manchester United are admirers of him.MEN Sport understand United manager Ole Gunnar Solskjaer regards Koulibaly as one of the best centre-backs in the world along with Virgil van Dijk, Matthijs de Ligt, and Harry Maguire, but they aren't expected to move for him this summer.United do not regard Koulibaly as an essential target and