Sir Bobby coached Sousa as a young player at Sporting Lisbon, and the pair became lifelong friends.
Paulo Sousa: "I hope his soul can come close to me and give me all the happiness, emotions and enthusiasm that he always had.
"I remember how he was on the sidelines, the way he motivated his players and I hope it can inspire me at Newcastle.
"I feel him all the time and will never forget him. His spirit will be there and next to me all the time.
"Bobby was a big influence for me. I always keep him in my heart. I never forget his face or what he did for me.
"He made me feel important, made me believe in myself and taught me a lot of how to be a better person. He was the one that taught me to be more enthusiastic and not so shy.
"Bobby deserves to be a hero in world football - he's someone who can't be forgotten in football."