Arsene Wenger has warned people not to be too surprised to see his old rival Sir Alex Ferguson return to football in the near future.
Ferguson retired after 26 years at the end of last season and was succeeded by David Moyes, but the former Everton boss has struggled to get going in his debut season at Old Trafford.
Upon his retirement, Ferguson vowed he would not be returning to football management, but the Arsenal boss doubted whether the Scot could be so absolute with his intentions.
Wenger said it was easier said than done and that walking away from the sport he has been immersed in for decades would take a great deal of will power.
"In six months we will know more about that," he told the BBC when asked if he thought Ferguson would stay retired.
"You cannot rule it completely out. It is difficult to take a drug for 30 years and suddenly get rid of it."
Ferguson was in the headlines all week after the release of his autobiography and the revelations about former players and rivals, such as David Beckham, Roy Keane and the Gunners boss.
Wenger said he had not read the book but felt like as though Ferguson had been planning what was to go in the book while he was still in charge at Manchester United.
"It looks like Ferguson had prepared his book while he was managing," added the Frenchman.
"I suspect he had written some of it at home at night, remembering things and thinking: 'that goes into my book!'."