Manchester United welcomed Cristiano Ronaldo back to the club in the summer of 2021 with open arms, but the mood soon turned sour in the dressing room and the Portuguese superstar eventually left 15 months later shrouded in controversy.
Mike Phelan worked with Ronaldo across both of his spells at Manchester United, first as Sir Alex Ferguson's assistant and later as Ole Gunnar Solskjaer's.
He witnessed first-hand the impact Cristiano Ronaldo had on the dressing room upon his return, suggesting players were unable to react positively to his mindset and demands.
"The second time round, he came in a lot older and a lot more opinionated, strong-willed," Phelan told Sky Sports. "He still had massively high standards and was terrific to work with. But I'd probably say a tougher mindset. He had been at Manchester United, he had been Portugal's ever-present, he had been at Real Madrid.
"I liked it because he didn't want his standards to drop, he wanted other people's standards to come up. And sometimes you lose a few people along the way when that happens. I remember certain times when he pushed and pushed hard, and he didn't get much reaction or much response. And there was frustration.
"When you deal with top, top people, it's about them and where they can finish and where they can get to. They want to look back and go 'wow, that was successful'. And he probably realised, and I don't know as I never had that conversation with him, that he couldn't do it at Manchester United. So his challenges were elsewhere."
VIDEO: What really happened between Jadon Sancho and Erik ten Hag
Phelan continued in the conversation, suggesting that Ronaldo helped improve him as a coach due to his constant desire for progression.
"He's a really good personality, hard-working and challenging. He challenged me as a coach, Carlos Queiroz as a coach and Sir Alex as a manager. But that's good because it takes you to another level.
"[The first time around] he had all the skillset, the mentality - but what we tried to do with Carlos Queiroz was we tried to integrate him into the team and he responded brilliantly. His work ethic and practice was fantastic and it rubbed off on the players. They knew there was someone special there.
"In that environment, with the standards so high, the players knew this guy could take them where they needed to go and to go again. He did that brilliantly."
More Manchester United and Cristiano Ronaldo stories
Man United legend Andy Cole has questioned why so many big-name players have seemed to struggle at the club in recent years.
Meanwhile, Mikael Silvestre has reflected on his United debut away to Liverpool in an interview with FourFourTwo.
Cristiano Ronaldo claims his role as 'pioneer' for the Saudi Pro League has helped attract star names.
