Premier League footballer Jermain Defoe has paid tribute to six-year-old mascot as his "best friend" and said he will continue to inspire him.
Bradley, whose battle with a rare childhood cancer captured hearts, died at home in Blackhall, County Durham, in his parents' arms on Friday, surrounded by his family.
He struck up a close friendship with the England and Bournemouth striker who hugged Bradley when the boy joined the footballer as a mascot on the pitch ahead of matches.
Defoe tweeted: "Goodbye my friend gonna miss u lots.
"I feel so blessed God brought u into my life and had some amazing moments with u and for that I'm so grateful.
"I'll never ever forget the way u looked at me wen I met u for the first time, the genuine love in those cute eyes.
"Really finding it hard to find words to express what u mean to me.
"The way u say my name, ur little smiles wen the cameras come out like a little superstar and the love I felt wen I was with u.
"Your courage and bravery will continue to inspire me for the rest of my life. You will never know what a difference you made to me as a person.
"God has you in his arms and I will always carry you in my heart. Sleep tight little one. My best friend. ,,)"
A week before his death, Bradley and Defoe were pictured snuggled up together at the youngster's home after the little boy had a party in bed as a way of saying goodbye.
Bradley was a mascot for his beloved Sunderland several times last season and struck up a remarkable friendship with the club's top scorer Jermain Defoe.
The youngster was also a mascot for England at Wembley and saw the man he called his "best friend" score in a World Cup Qualifier against Lithuania in his comeback game.