Ronaldo returned to Man United in 2021-22 with fans across the globe confident it would herald a brave new era at the club.
The legendary Portuguese forward scored 24 goals in his 38 games across all competitions that season, but United ended the Premier League season in sixth.
Ole Gunnar Solskjaer was sacked mid-season and Ralf Rangnick came in on an interim basis before Erik ten Hag was named as the new manager.
Ronaldo’s relationship with Ten Hag was strained to say the least and Maguire, 32, has looked back on their time together.
Speaking on Rio Ferdinand Presents, Maguire said: "I can’t speak a bad word about him. It was amazing to have him. When he walked through the door, it was just incredible. It was just so disappointing how it ended and how we couldn’t find a way to perform with him in the team.
"He was performing, he was scoring goals, it was crazy. We were rubbish and he was still scoring goals, so it just shows how good he is.
"We just couldn’t find a way to… all our system under Ole was about being on the front foot, being aggressive. Pressing, it was like a pressing machine. And obviously Cristiano came in and we just didn’t adapt well enough for him, and you could just tell he was so upset and frustrated."