Johnston can play at either left back or left centre back and has featured for Scotland at under 21 level as well as the Premier League 2 team for Liverpool.
It would be an interesting development if a loan move was arranged. Hughes was the mainstay at left back last season. It has been rumoured that youngster Josh Earl may well go out on loan next season given he had trouble adapting last season after an impressive first term at Preston.
Johnston could also be used for back up for the centre back position and Neil is attempting to add strenght in depth to his squad as he aims to move Preston higher up the table.