Courageous Bradley Lowery went along to the Stadium of Light before being mascot at the game tomorrow night.
Football fans of all colours have been staging tributes to the five-year-old who is battling cancer neuroblastoma.
His family were given the devastating news last week that the youngster will lose his fight with the illness and thousands of people have been showing their support for the Blackhall youngster.
Tomorrow night Bradley will be led out onto the pitch at the Stadium of Light to be mascot as his beloved team takes on Chelsea.
However, on Monday, he went along to the SAFC ground and met with manager, David Moyes.
Mr Moyes said: "We had a special visitor in the training ground on Monday. Bradley came in late afternoon and we took him down the gym and around the swimming pool.
"He had the boxing gloves on and he was running around for about half an hour and said hello. It was good to see him.
"The players didn't see him, he came in late about 4.30pm but he is obviously at the game against Chelsea.
"We are very privileged the position we are in, the players especially, so it is nice to give something back.
"It was great to see him. Sometimes it is just inspiration to see young people like that."
Bradley's mum, Gemma, said Sunderland AFC had given the youngster a Harry Potter Studio Tour in London for Christmas.
She said: "Bradley was over the moon with this and mega excited to go.
"He is also getting the chance to score a goal tomorrow at the pre match warm up so if you going to the match he would love all your support to cheer him on. I can't thank Sunderland enough for the support they are showing us and helping our family make special memories."