According to Amir Khan, former world champion Anthony Joshua should consider taking "one or two fights" to rebuild his career - before he takes part in a rematch with Andy Ruiz.
On June 1, Ruiz shocked Joshua, by dropping the Olympic gold medal winner four times before the contest was waved off in the seventh round.
Ruiz walked away with the IBF, WBO, IBO and WBA world heavyweight titles.
Joshua has already exercised an immediate rematch clause, and plans to face Khan in the fall.
Khan, who usually took some easier fights in the aftermath of defeat, believes Joshua is making a big mistake.
"I don't think he should fight Ruiz straight away," said Khan to BBC Sport.
"If he fights him again, it will be very hard to overcome that. I thought it would be very good for Joshua to have one or two fights to rebuild himself and his confidence. Not that he needs it but while you have the opportunity to do that, you might as well. In boxing, people just want to see you in harder and harder fights. Had he won, people would want him in with Deontay Wilder or Tyson Fury. He's so young as a heavyweight, this would give him a chance to improve on things and come back stronger.
"Then when it does come to be time for Wilder and Fury, he would be more than ready. Maybe defeat by Ruiz will be a blessing for him. There's always pressure on you when you get beaten. You think: 'Do I still have it in me?' People start saying you're not what they thought you would be. That does affect you mentally. You have to use the criticism as motivation.
"Getting beaten so early in my career, I learned to build myself up again. I had to prove people wrong - and becoming a world champion was a good way to stop critics. It was hard to take at the time but it was probably the best thing that ever happened to me as it made me a better fighter mentally."