Zak Hardaker has been warned his move to Wigan is his "final opportunity" to get his career back on track.
The England international has signed a four-year deal with the Warriors and will join the Super League club once his drugs ban ends in November.
The 2015 Super League Man of Steel is serving a 14-month suspension imposed by UK Anti-Doping after testing positive for cocaine while he was a Castleford player.
He was sacked by the Tigers after they were informed of the test, which took place in September 2017 and was confirmed in April.
Wigan confirmed the 26-year-old would be free to join the club officially on November 8, and permitted to train with them two months before that.
But club chairman Ian Lenagan warned that Hardaker cannot afford anymore controversies.
Lenagan said: "This wasn't a decision that we made lightly. We recognise the serious nature of this incident and our choice in offering this opportunity should not be seen as condoning his actions in any way.
"We had extensive conversations with Zak and his family before making our offer.
"We encountered a man who, after eight months of reflection, openly admits that he has made a series of significantly poor decisions over the past few years.
"Crucially, we also saw someone who recognises that this is the final opportunity to focus on delivering the achievements his talent should generate.
"I have had the experiences in business and sport of offering contrite individuals the final opportunity and environment to learn from their mistakes with some notable successes and occasional failures.
"Wigan are giving Zak Hardaker that platform to repay the faith his family have shown him.
"My team at Wigan will manage, mentor and test him through this period of rehabilitation and development and, hopefully, guide him back to being one of the best players in Super League."
Hardaker won both the Super League Grand Final and Challenge Cup on two occasions during his time with Leeds.
Hardaker joined Castleford initially on loan in the autumn of 2016 before making the move permanent the following June.
He was left out of the Tigers' Grand Final squad in October 2017 to face his old club after the adverse drugs test came to light.
Wigan coach Shaun Wane added: "Zak is an outstanding competitor and a hugely talented individual who will understand the culture at our club.
"He is the opposition name who, when we preview his team, is always the main danger. Now he is on our team and that is pleasing for everyone involved."