The 25-year-old has become a cult hero in Spain after spending the second half of the season on loan at Real Betis from United.
Antony recently admitted he considered retiring from football while in England after failing to live up to the £86 million price tag at Old Trafford.
After rediscovering some form and his love for the game at Betis, the winger penned an emotional message on Instagram to the fans who gave him a second chance.
"Today is the day to give thanks for one of the most beautiful chapters of my life. And as I write this page of my story, I need to say why you were and always will be so special to me," he said.
"From a young age, football was not just a dream or my only chance to change my life, as so many say out there. For me it was more than that. It was my joy. While many saw football as a way out, I saw football as a way in.
“The only place where I felt complete. I counted the minutes to run after the ball. Playing wasn't an escape, it was a destiny. It was pure happiness. Life took me far away, from the favela to the world. I left Brazil, I played in Holland, I played in England. I stopped being just a kid and became a father. Many things changed.
"But football, football was always there. It was always my refuge. Until one day, everything fell apart. From heaven to hell. The ball stopped going in, the joy disappeared, my world darkened, and I began to doubt myself. My talent and my passion for football. That's when football gave me one last gift. You.
"When I arrived here, I didn't know what to expect. But even in my wildest dreams, I imagined finding what I found. From my first step at this club, I felt something different. It was like coming home, like finding a part of me I thought was lost.
“With you, I smiled again. With you, I found the child I was before. The one who loved football with all his heart. With you, football became love again. True love. Thank you for welcoming me like one of the family.
“Thank you for giving me back the joy of playing football. And thank you for reminding me why I fell in love with this game. My home, my people, always so much Betis."