Arsenal manager Arsene Wenger on Friday said he wouldn't be surprised to see Alex Ferguson go back on his decision to retire.
Former Manchester United manager Ferguson quit Old Trafford at the end of last season after 26 and a half years in charge.
The Scot was back in the headlines this week with the publication of an updated autobiography which included a number of stinging rebukes aimed at the likes of David Beckham, Roy Keane, Steven Gerrard and Rafael Benitez.
Wenger has his own dedicated chapter in the book, entitled 'Competing with Wenger' - much of which is centred around the infamous 'pizzagate' at Old Trafford in October 2004 when United ended the Gunners' 49-match unbeaten Premier League run.
The Gunners boss had a spikey relationship with Ferguson at times, but they are more friendly these days.
And Wenger, now the longest-serving manager in the Premier League following Ferguson's retirement, is not certain it will be easy for his old rival to just simply walk away forever and the Frenchman suggested he could even change his mind in the next six months.
"In six months we will know more about that (whether Ferguson will return to football). You cannot rule it completely out," said Wenger ahead of his side's Premier League fixture at Crystal Palace on Saturday.
"It is difficult to take a drug for 30 years and suddenly get rid of it."
However, after witnessing the storm of controversy that greeted Ferguson's book, Wenger has no intention of writing his own memoirs just yet.
"We are in a job that is a good teacher of humility, because we have to accept that everybody can judge our job at any moment without completely knowing all the ingredients of our job," he said.
"But it is part of it, with the positive and the negative.
"Sometimes they give us credit we don't deserve as well, but we have to take both sides.
"It looks like Ferguson had prepared his book while he was managing - I suspect he had written some of it at home at night, remembering things and thinking: 'that goes into my book!'."