Its quite clear that although Daley Blind has put in an admirable shift as a CB this season, it's not a long term option for our club. He has over-performed as a CB throughout the season, but simply put he shouldn't play CB next year. Here are some reasonable options I believe we should be going for this summer:

Koulibaly

Manolas

Marquinhos

Laporte

Ginter

Van Dijk

Mustafi

Rudiger

Who do you realistically see coming to United this summer? Or is there another defender waiting for a big break in our Academy?