"Adrian wanted to work with Tony as he was a high-profile sportsman who overcame an addiction," Sporting Chance's Peter Kay has told BBC Sport.
"I'm sure he'll take the chance to learn important lessons about himself and become the man he hopes to be.
"Because of the public nature of Adrian's ban and its conditions, I can confirm he will be with us in the new year.
"In many ways it will be the biggest challenge of his career.
"Adrian has done everything that has been asked of him up to now.
"He is a delightful young man but like many, including me, he's made a mistake in his life."
Mutu, who was sacked by Chelsea last month, will begin rehab at Sporting Chance in January.