Born in the Viewpark area of North Lanarkshire, Robertson played for Drumchapel Amateurs and Scotland at youth level before joining Forest in May 1970, making his debut later that year.
Having been on the transfer list before Clough’s arrival in 1975, he became a key player under the iconic manager, appearing in 243 consecutive games between December 1976 and December 1980.
Robertson scored the winner from the penalty spot in the 1978 League Cup final replay win over Liverpool.
He was sold to Derby in 1983 for a constested transfer fee, a move which soured the relationship between Clough and his former assistant, Peter Taylor.
An early injury hampered Robertson’s progress at County and, despite rejoining Forest in 1985, he never again captured the same form and moved on to non-league Corby Town, Stamford and then Grantham Town.
At Forest, he also won the First and Second Division titles, the Uefa Super Cup, two Football League Cups, the 1978 FA Charity Shield and the Anglo-Scottish Cup.
And in 2015, Robertson topped a poll by the Nottingham Post of favourite all-time Forest players.
As O’Neill’s assistant, Robertson helped Wycombe win promotion from the Football Conference and Third Division, and promotion to the top tier with Leicester, as well as the League Cup.
An even more successful spell with Celtic followed.
In Glasgow, they won the Scottish Premier League three times, the Scottish Cup three times, the League Cup once and reached the Uefa Cup final.
Then, in Robertson’s final season as a coach in 2010, Villa finished runners-up in the League Cup final.