Liverpool have been linked with Robertson on and off for the past few seasons, with interest from Anfield picking up again once more as the 2016/17 season drew to a close.
Versatile midfielder James Milner was forced to fill in at left-back for the whole campaign after manager Jurgen Klopp lost faith in the often defensively suspect Alberto Moreno.
Born in Glasgow, Robertson began his career in the youth academy at Celtic only to be released at the age of 15 over concerns about his physical size. He then joined QPR and returned to Scotland as a professional with Queen's Park and then Dundee United.
Robertson arrived at Hull in 2014 when the Tigers were newly promoted to the Premier League. He then helped the club return to the top flight with Championship promotion and subsequently played 33 of Hull's 38 Premier League games last season.
The 23-year-old has played 15 times for Scotland since his senior debut in 2014, scoring his only goal to date against England at Celtic Park that same year.