Former Manchester United assistant coach Mike Phelan admits Cristiano Ronaldo's teammates couldn't match the standards he demanded from them.

Ronaldo spent 18 months at Old Trafford during his second spell with the club before terminating his contract by mutual consent.

Phelan worked with Ronaldo in the first season and recalled to Sky Sports: "The second time round, he came in a lot older and a lot more opinionated, strong-willed.

"He still had massively high standards and was terrific to work with. But I'd probably say a tougher mindset. He had been at Man United, he had been Portugal's ever-present, he had been at 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."