Anthony Joshua's trainer criticised his performance in the victory over Wladimir Klitschko on the fighter's first morning back in the gym.
Despite winning what was widely considered the finest world heavyweight title fight since the 1990s so conclusively that Klitschko has since retired, Rob McCracken sought to maintain Joshua's focus.
The 27-year-old WBA and IBF champion became Britain's latest darling with the 11th-round stoppage victory in front of a 90,000-strong crowd at Wembley, and has since largely experienced only praise.
He returned to the gym only four weeks after the April 29 date in an attempt to "tick over" until confirmation of his next fight, expected imminently against Bulgaria's Kubrat Pulev for either October 28 or November 11.
When he did so however, McCracken, also Team GB's performance director, immediately told him he needed to improve.
"It was like I was a novice," Joshua told Press Association Sport.
"We ticked the entertainment factor, but from a coaching point of view there was a lot of mistakes made, and a lot of things we could do better, and that's what he looks at.
"He was straight up: 'Yeah, great, whatever, but that was four weeks ago; we've got to start preparing for the next three years. Not only are there tougher fights in front of you, there's other people gunning for you to beat you, so you've got to get serious'.
"'You've got to get back on it now. Your left hook was bad'. I was still living off the adulation, thinking: 'What? This guy's taking the Mick'. But I'm over it now.
"Let's say you've painted something and you think: 'Yeah, that was great', and then someone sees it and they're like: 'Yeah, it's all right'. Everything you thought it was, someone told you it wasn't. The fight's done. No hype, let's get back to business.
"That's why I went with him when I turned pro, because I knew I needed a lot of experience, and he knew me for who I am in the gym. After the Olympics certain people would have thought: 'This kid's unbelievable' but Rob was like: 'No, you're a novice, you've done well, but.' - he's always been grounded."
April's victory was the second of significance McCracken has experienced at Wembley after he also trained the retired Carl Froch to his 2014 defeat of George Groves.
Joshua had hoped to fight the 41-year-old Klitschko again in Las Vegas, but since the Ukrainian's retirement Pulev, 36, has become his focus.
"The confirmation of the fight will come from us," he said. "The best thing I've done is maintained; you can have a rest and feel worse than you did while training.
"I actually feel decent because I've been ticking over. I need to improve, get better, and the only way to do that is keep training, sparring."