Ronaldo was thought to be on the verge of joining Manchester City from Juventus before Man United re-signed him in August 2021.
The Portugal international scored 24 times for the Red Devils during the 2021-22 campaign, but he only managed three goals in 16 appearances in the first half of the 2022-23 season before his contract was terminated following an explosive interview with Piers Morgan.
Solskjaer has admitted that he had difficulties changing the team's style of play upon Ronaldo's return and also said that there were "complications" that came with the Portuguese making the move back to Old Trafford.
"We started off straight away thinking how we are going to press and change the little tweaks," Solskjaer told the Stick to Football podcast. "Cristiano is different to Antony Martial who was up front, or whether we would play Mason [Greenwood] or Marcus [Rashford] up front.
"Edinson Cavani was the one that suffered the most when Cristiano came in - we'd played and got Edinson into a certain way of understanding the way we played.
"With the ball, with him in the team, it was no problem. Without him [pressing], we had to change a little bit the different roles we'd gotten used to. We were one of the highest pressing teams before [Ronaldo joined]. We let Dan James (Daniel James) go when Cristiano came in, and they're two different types of players.
"Part of signing Cristiano Ronaldo was getting that passion from him, but that did have its complications.
"You've got Mason Greenwood, Marcus Rashford and Anthony Martial, who can learn from Cristiano as he's the best, the most disciplined and he's been the best player in the world, and you think he's going to help them.
"When he arrived at the club, he told me to start him for three games in a row, and then put me on the bench for the fourth game, but he's so passionate so when I did that, he didn't like it.
"It was a very quick decision. We didn't think Cristiano was available and that he was going to move. When it became apparent that he was leaving Juventus, obviously there were other clubs that wanted him - but I was excited.
"They [United] asked me, "Would you want us to try this?". I said yes - obviously we know Cristiano is quality, and he's 37, but we have to manage - he's the best goal scorer in the world. It didn't work out for me, it didn't work out for Cristiano, but it was the right decision at the time.
"When I was manager of Manchester United, I can't remember too many problems from Cristiano Ronaldo. It was the game against Everton when he walked straight off the pitch after I brought him on as a substitute, but there were more problems with him after I had left the club.
"I had a good relationship with Cristiano and there's loads of respect between us. I think he behaved really well in his disappointments when I was there."
Ronaldo has been with Saudi Arabian outfit Al-Nassr since January 2023, and the 39-year-old has scored 42 goals and registered 13 assists in 49 appearances for the club in all competitions.