The Manchester United legend's meetings with Mandela included one in July 2006 when he was joined by Sir Alex Ferguson and his first-team players during the club's pre-season tour of South Africa. The Reds presented the world-famous statesman with a shirt to mark his birthday, at the Johannesburg offices of the Nelson Mandela Foundation.
Mandela was 95 when he passed away on Thursday. Sir Bobby told us: "I was deeply saddened to hear the news of Nelson Mandela's passing. My thoughts and prayers are with his family and the people of South Africa and whilst we will all mourn his death we should also celebrate his life, and what a life!
"Mr Mandela worked tirelessly all of his life for racial equality and his legacy will live on way beyond our lifetime. I feel blessed to have lived during his life span and privileged to have met him on a number of occasions. God bless my friend, Madiba."
When United last played in South Africa in July 2012, Sir Alex went on national television there to join in the celebrations for Mandela's 94th birthday. He said at the time: "The thing that strikes me most of all about Nelson Mandela – and I've met him two or three times – is that there's no bitterness about him. After what he endured and suffered, he has no bitterness. You have to be special to do that, to put that to one side, to try to get on with life and try to influence your country in a massive way. He's an example to the world."