The former PSV, Barcelona, Inter and Real Madrid superstar was widely recognised as one of the finest players of his generation.
Ronaldo went to four World Cups with Brazil and won both the Golden Boot and the Silver Ball in their 2002 success, having played no part in the Selecao's 1994 triumph.
But he remarkably only won two domestic league titles (both in LaLiga with Madrid) as his career was hampered by injuries.
In a new documentary on DAZN, Ronaldo discussed mental health in football with former Madrid and Brazil team-mate Roberto Carlos.
And 'O Fenomeno' was asked further about his own struggles in an interview with Marca, confirming he had suffered from depression.
"Today I am in therapy," Ronaldo said. "I have been in therapy for two and a half years, and I understand myself much better than before.
"But then again, I'm from a generation in which you were thrown into the arena and you had to do your best without the slightest hint of drama.
"I look back, and I see that yes, we were exposed to a very, very big mental strain and without any preparation for it.
"Also because it was the beginning of the internet era, with the speed at which information travels. At that time, there was no concern about the mental health of the players.
"Today players are much better prepared, they are given the medical attention they need to face the day to day, and players are studied more: the profiles of each player, how they react, how they should react.
"In my time, there was none of that, unfortunately, because we have known all our lives that soccer can cause a lot of stress and be very decisive for the rest of our lives."
He added: "The reality is that we didn't even know this kind of problem existed. It was absolutely ignored among our generation.
"Many, obviously, have gone through terrible times, even depression, because of the lack of privacy, the lack of freedom.
"It is true that the problems were very obvious, but the solutions were not very available."
Messi's consistency over such a long period has made him the finest player Argentina has produced according to Cassano, who has called for Maradona's fans to accept that the Barcelona talisman deserves to be recognised as the best.
Cassano helped Real Madrid to the 2006-07 LaLiga title at the expense of Barca and Messi, but that success in Spain has not altered his opinion on the forward.
"Maradona did something never seen before for four or five years, but Messi has done the same things for 15 years," he said in an interview with Corriere dello Sport.
"He has made 710 goals and 300 assists. When he plays you start with a 1-0 lead.
"The ‘Maradonians’ have to accept it: there is someone who has ousted him."
Cassano revealed that, prior to Messi moving to the top of the list, he believed Brazil striker Ronaldo – a former Madrid team-mate - was the game's greatest.
"We were losing 1-0 at home," Cassano recalled. "The whole stadium was whistling, especially him [Ronaldo].
"In the locker room the coach removes Ronnie to put [Ruud] Van Nistelrooy on, but he [Ronaldo] stops him and says 'no, you take me off in 15 minutes if I haven't scored two goals'.
"Minute 15: 2-1 and two goals from Ronaldo. I said that if there is a football god, it is Ronaldo. Then I discovered that Messi is above him."
Barcelona and Argentina maestro Messi is "surely" the best footballer of all time, former Real Madrid and Barca playmaker Prosinecki claimed.
Prosinecki said in an interview with Stats Perform News that Messi, who has scored over 600 goals for Barcelona, still finishes top of the pile when the career of Chicago Bulls legend and six-time NBA champion Jordan is taken into account.
"It is different, basketball and football. But Messi is surely for me the best," said Prosinecki.
"He is a player who has made differences for many years in Barcelona. He has won everything he could win. He scored many goals and assisted many times too. He plays different football to the others."
Former Croatia midfield marauder Prosinecki knows some still look to Messi's fellow Argentinian Maradona when judging the greats, as well as two-time World Cup winner Ronaldo.
Prosinecki and Ronaldo were briefly team-mates at Camp Nou.
"Maybe some people will say Maradona, Ronaldo... I don't know," Prosinecki said. "There have been amazing players. They are from two different eras. For me he [Messi] is the best one."
According to Prosinecki's verdict, Messi and Brazilian Ronaldo are players that have shown themselves capable and willing to take on teams single-handedly.
"They are different to others. Ronaldo is surely one of the best," Prosinecki said.
"Some people would say Cristiano Ronaldo, but [Brazilian Ronaldo] didn't just play at Barcelona.
"He also had some amazing seasons at Inter. He used to beat rivals almost himself alone. Incredible. They are players who make differences. At Real Madrid too. Where didn't he perform?
"For sure he was a great player. However, if I have to say one, for me the best is Leo Messi."
The Albert Einstein Israelite Hospital in Sao Paolo confirmed multiple organ failure was the cause of death for the 82-year-old, who had battled colon cancer throughout the latter stages of his life.
Pele was accompanied by his family before Christmas Day after he had been moved to palliative care earlier in December when his body had stopped responding to initial cancer treatment.
Tributes have flooded in from numerous sporting icons, clubs and organisations after the passing of whom many regard as the greatest footballer of all time.
Legendary striker Ronaldo followed in the footsteps of the three-time World Cup winner and believes Pele's impact will never diminish.
"Unique. Cool. Technical. Creative. Perfect. One of a kind. Where Pele arrived, he stayed. Without ever leaving the top, he leaves us today," Ronaldo, a two-time World Cup winner himself, wrote on Instagram.
"The king of football – only one, the greatest of all time. The world is mourning. The sadness of parting mixed with the immense pride of the written history.
"What a privilege to come after you my friend, your talent is a school every player should go through. Your legacy will transcend generations. And that's how it will stay alive.
"Today and always, we celebrate you. Thank you, Pele. Rest in peace."
Legendary forward Ronaldo led Brazil to their most recent World Cup triumph 20 years ago, scoring eight goals as Luiz Felipe Scolari's team sealed the country's fifth title in Japan and South Korea.
No Brazilian has ever bettered Ronaldo's tally at a single edition of the tournament, while his total return of 15 World Cup goals has only been beaten by Germany's Miroslav Klose (16).
While Ronaldo believes his exploits put him in the pantheon of footballing greats, he told the Guardian it was difficult to compare his abilities to those of players from different generations.
Asked to choose between seven-time Ballon d'Or winner Messi and another Argentina icon in Maradona, Ronaldo said: "That's unfair!
"I think there is a very, very special group where you have Diego, Messi, [Johan] Cruyff, [Franz] Beckenbauer, Pele, [Marco] Van Basten, Ronaldinho. I would include myself.
"Let the fans say, let them debate it in the bars. But you can't rank them, can't compare generations.
"People call me the 'original' Ronaldo but there were others – and they weren't false.
"I'm not the only one, and more will come along and be better than me in everything. I did what I could, the best I could."
Brazil's hopes of repeating their 2002 World Cup win will depend largely on the form of Neymar, who has been involved in 42 per cent of the Selecao's World Cup goals since making his tournament debut in 2014 (8/19 – six goals, two assists).
Ronaldo compared the abilities of the Paris Saint-Germain forward to those of Messi and Cristiano Ronaldo, insisting no football fan could fail to enjoy watching him play.
"People love him a lot," Ronaldo added of Neymar. "If we talk specifically about football, I doubt there's anyone who doesn't love him. His private life transcends football, but I'm not interested.
"He's daring, has skill, variety, is quick, scores goals, has personality. You could compare him to Messi and Cristiano Ronaldo, even though they are from a different planet.
"On the pitch Neymar is one [thing], then people mix in all the other stuff."
The French publication presented its all-time dream team on Monday, with Juventus superstar Ronaldo named alongside Barcelona's Lionel Messi, Pele and Diego Maradona – who died last month.
Brazil great Ronaldo, former Milan captain Paolo Maldini, Xavi, Bayern Munich legend Franz Beckenbauer, Lothar Matthaus, Cafu and goalkeeper Lev Yashin completed the XI.
Reacting to his inclusion, five-time Ballon d'Or winner Ronaldo tweeted: "I'm very honoured to be part of France Football's All Time 11."
"What an amazing Dream Team... They all deserve my respect and admiration and I'm obviously proud to be amongst such extraordinary players. Thank you!"
Cristiano Ronaldo – Real Madrid's record goalscorer – has won five Champions League titles, three Premier League trophies, Euro 2016 glory, two Serie A crowns and as many LaLiga triumphs to go with numerous other silverware.
Ronaldo celebrated his 100th Juventus appearance with a brace in Sunday's 3-1 Serie A win over Genoa.
Not only was Ronaldo making his 100th Juve appearance, he also became the first player to reach 400 wins across Europe's top five leagues this century.
Additionally, Ronaldo – who has netted 77 times since joining Juve in 2018 – reached 31 goals for the calendar year, making him the third Bianconeri player to reach this milestone in the top flight, and the first since Omar Sivori in 1961.
Serie A holders Juve face Atalanta on Wednesday, with the 35-year-old Ronaldo looking to add to his 10 league goals this term.
Brazil were dumped out of the World Cup by Croatia on penalties on Friday, despite Neymar putting Brazil a goal up in the second half of extra time.
Bruno Petkovic's deflected finish pegged Brazil back with four minutes left to play, and Rodrygo and Marquinhos missed their spot-kicks as Croatia reached the semi-finals for a second consecutive tournament.
Neymar was due to take the fifth penalty for Brazil, but his team-mates' misses meant he never got the chance and the Paris Saint-Germain star was left in tears after the conclusion of the shoot-out.
Ronaldo, who won the Golden Boot as Brazil lifted the 2002 World Cup, hopes Neymar will bounce back from his disappointment in Qatar.
"I think at the moment he is upset by the elimination," Ronaldo told reporters on Monday. "It's normal for him to feel that way but I'm sure he'll come back stronger and keep playing for the team.
"He is still young, and I believe he can play in the next World Cup. I am very happy that he has shown the world his commitment to the national team and that he has taken care of himself over the past six months.
"It's very important to us, so I hope he will recover quickly and come back stronger with PSG and the Selecao."
Ronaldo feels Brazil's lack of ruthlessness in Friday's quarter-final defeat ultimately cost them a place in the final four, explaining: "Brazil had a great World Cup.
"We only lacked the vice, that is to say knowing how to waste time when you are leading. After this goal in extra time [Neymar's strike to put Brazil 1-0 up], the match should have been over.
"You have to know how to circulate the ball well and chase the opponent, keep it away from the goal. You need this little trick, be smart. I think that's the only thing we lacked against Croatia."
Brazil arrived in Qatar as the favourites to win the tournament a record-extending sixth time.
But their exit looks to have opened the door for reigning champions France to become the first team to retain their World Cup crown since Brazil did in 1962.
Ronaldo views Les Bleus as the team to beat now, with Didier Deschamps' side set to face Morocco in the semi-finals on Wednesday.
"My forecast, before the start of the World Cup, was a final between France and Brazil," the 46-year-old declared. "Brazil is no longer there, but France confirms with each match that it is one of the favourites.
"I even think it's the big favourite. France has a very solid team, both in defense and in attack."
France's Kylian Mbappe has been one of the stars of the World Cup, and currently leads the goalscoring charts with five in five games at the tournament.
Ronaldo lauded the 23-year-old's abilities, saying: "Mbappe is having a very good World Cup. He has incredible physical and technical qualities, for me he will be the best player in the World Cup.
"He reminds me a bit of me when I was playing. He knows how to use his skills, his speed and his power, how to go faster than the others and use them to pass or score. He is impressive."
The two-time Ballon d'Or winner, who top-scored in Brazil's 2002 World Cup triumph, has been experiencing mild symptoms of the coronavirus.
Ronaldo had been due to attend events marking Cruzeiro's 101st anniversary, but the 45-year-old former Barcelona, Real Madrid and Inter striker was instead isolating.
His positive case was announced by the Brazilian club, who were acquired by Ronaldo, with the support of an investment bank, in December.
"Cruzeiro reports that this Sunday morning Ronaldo Nazario tested positive for COVID-19," the Campeonato Serie B club said.
"This makes it impossible for him to travel to Belo Horizonte today, as well as his presence in the commemorative actions for the club's anniversary.
"Ronaldo is doing well, with mild symptoms and, on medical advice, is now in rest and social isolation."
Ronaldo has been majority owner of Spanish club Real Valladolid since 2018 and serves as the Segunda Division team's president. He had been due to meet with representatives of Cruzeiro supporters on Sunday and was scheduled to appear at a news conference on Monday before taking ill.
He began his playing career at Cruzeiro as a teenage sensation before heading to Europe to join Dutch giants PSV after the 1994 World Cup.
Ronaldo wrote on Twitter: "Cruzeiro nation, this is not the way I wanted to spend this January 2 which is more than special for us.
"I had the greatest anticipation and everything was organised for this moment. But there are situations in life that are beyond our control and, unfortunately, last night I found myself in one of them. I started to feel bad, had a PCR and woke up today with a positive result for COVID-19.
"The most important thing is that I am vaccinated, I will follow the isolation protocols and, at the end of it, I hope to be 100 per cent recovered to resume my schedule.
"Our meeting was not cancelled, it was postponed due to circumstances. And I make a point of celebrating with you the anniversary of our club! It's just the beginning of our fight together! I count on you, count on me."
Ronaldo played under the Italian coach for six months at Real Madrid before being sold to Milan in January 2007, having scored 104 goals in 177 appearances for Los Blancos.
The Brazil icon made just seven LaLiga appearances, scoring once, in that campaign after finding himself out of the team due to the arrival of Ruud van Nistelrooy and arguments over his weight.
Capello, speaking to Sky Sport Italia, had no doubts about Ronaldo's natural gifts but said his partying antics were a cause of consternation.
"The greatest talent I ever coached was Ronaldo," he said.
"But at the same time he was the player who created the most problems for me in the dressing room.
"He used to throw parties and do everything. Once Ruud van Nistelrooy said to me 'coach, the dressing room smells like alcohol'.
"Then Ronaldo went to Milan and we started to win, but if we're talking about talent then he was the greatest, without a doubt."
Madrid went on to win LaLiga under Capello in that campaign, while Ronaldo was released by Milan at the end of the 2007-08 season – during which he sustained a serious knee injury.
It has already been a memorable 2024 for Vinicius, who played a starring role as Madrid regained the LaLiga crown, before scoring in their Champions League final victory over Borussia Dortmund at Wembley.
The winger top-scored for Los Blancos with 24 goals across all competitions, with the likes of Carlo Ancelotti, Jude Bellingham and Neymar insisting his exploits are worthy of winning the Ballon d'Or award.
Vinicius would be the fifth Brazilian to win the prestigious accolade after Kaka, Ronaldinho, Rivaldo and Ronaldo (twice), with the latter believing it is a formality.
"He's been extremely decisive this year for Real Madrid," he told ESPN Brasil. "For me, today he's the best player in the world by far.
"I think Vini already deserves [the Ballon d'Or]. I think his time has come. He's had a spectacular Champions League, a spectacular LaLiga, and he's been evolving more and more.
"I remember that I did his presentation the day he arrived at Real Madrid and I got on well with him. I talk to Vini a lot about football and certain details and, looking at everything that's happened, it's a fantastic development that he's making."
Vinicius now turns his attentions to the Copa America, where Brazil are among the favourites to land the crown in the United States.
Rivaldo, who won the Ballon d'Or in 1999, concurred with Ronaldo, and thinks the 23-year-old would be guaranteed the award should he lead the Selecao to glory.
"He deserves the Ballon d'Or," the former attacking midfielder said. "Of course, there's nothing better for him than to secure the award once and for all than by winning the Copa America now, right?
"Today, he already deserves the award, but if he wins the Copa America, even better."
