(CNN) He fought his way to 11 grand slam titles -- including fierce battles with his biggest rival, John McEnroe.
But former world No. 1 Bjorn Borg has been taken aback by what he's seen on the junior tennis circuit in Sweden.
"When we're traveling around Sweden we see all these crazy parents, I mean it's unbelievable," said the star in a rare interview with CNN Open Court's Pat Cash.
"Even during our time it was parents who were a little bit crazy in one way, but today it's unbelievable ... it's shocking.
"I think that's because tennis is a sport with a lot of money involved and you can see sometimes the kids don't want to play. It's like the parents push them to do something they don't want to do."
The tennis icon, who recently turned 60, travels to matches around Sweden with his youngest son Leo. The 13-year-old, son of Borg's third wife Patricia Ostfeldt, is "completely nuts about tennis" and represents the Under-14s for Sweden's prestigious Royal Lawn club.
Read: Bjorn Borg: 'Tennis is one of the cleanest sports'
Returning to the circuit as a tennis dad brings mixed feelings for the enigmatic Swede. A grand slam champion by 18, he grew tired of tennis and traveling and quit the game aged just 26 -- to the great surprise of the sport and his fans.
"[Leo] has a big heart for tennis," said Borg. "He plays for two or three hours every single day. He likes to play, he likes to compete, he likes to travel.
"So we have this big discussion -- myself, Patricia and the family. He wants to go out to Europe, he wants to play all the time, but he's still in school."
"I've come to a point where I don't want to travel that much. I like to stay home, I'm getting a bit older. I've traveled all over the world not only one time, but a hundred times."
Borg's eldest son, Robin, whose mother is the Swedish model Jannike Björling, was also a skilled tennis player -- he played men's college singles at the University of Wisconsin-Whitewater.
But Robin, now 30, said he had "no interest" in playing pro tennis and instead pursued a career in business -- he's involved in the Bjorn Borg clothing brand.
In tennis, parental support comes in varying shades but is often seen as key to reaching the top echelons of the game.
In Britain, Judy Murray's tireless commitment can be credited with shaping sons Andy and Jamie's success.
Read: Judy Murray: 'Andy and Jamie were always fighting'
In Borg's case, it was a gift from his own dad -- a tennis racket won in a local table tennis competition -- that sparked his inimitable career.
But the dual parent-coach role isn't always seamless.
Australian John Tomic served a suspended sentence of eight months for head-butting his son Bernard's training partner outside a Madrid hotel, leaving him with bloodied and broken nose.
The father of French-American champion Mary Pierce reportedly yelled "Mary, kill the b***h!" during one his 12-year-old daughter's junior match.
Peter McCraw is a world-renowned tennis development coach who has worked with players including Maria Sharapova and Jelena Jankovic. He says that while most parents get it right, the sport's individual nature and the huge commitment involved can breed "overly-involved" parents.
"There is tremendous pressure," explains McCraw. "The parents are making huge sacrifices and commitments in time and financial outlay. The opportunity-cost to do this is so great that a parent can't help but be overly-committed."
To give their child the best chance of a tennis career, McCraw says that parents typically spend around $10,000 a year on training, travel and tournaments for an eight to 12-year-old child. At the 16-18 age group this rises to $35,000, while for over 18s, the cost can reach $50,000 a year.
In the 2009 documentary "Trophy Kids", which follows overbearing parents in sports, one British father claimed to have spent $180,000 (£125,000) on his 12-year-old daughter's tennis training over an 18 month period.
"As the Americans would say, 'A tennis parent has more skin in the game'," said McCraw. "What an overly-committed parent makes the mistake of doing is imposing adult expectations on their child: Because they're spending this money, you have to win."
While the cost isn't likely to trouble the Borg family, for others the sacrifice can be crippling. The commercialization of the sport has also led tennis federations to start talent scouting younger -- development camps that once began at 14 now begin at eight in some countries.
The intense level of pressure in tennis has been well-documented. American tennis legend Andre Agassi described it as the "loneliest sport" in his 2009 autobiography "Open".
He and his wife Steffi Graf, who have 30 grand slams between them, reportedly discouraged their three children from playing -- their eldest Jayden is instead a keen baseball player.
There are relatively few second generation tennis players in the high levels of the game, according to McCraw.
"Not all players had a positive experience in tennis," he said. "So the moral decision to expose or not to expose ... it's healthy up to a certain dose and beyond that it can be quite destructive."
Given his early retirement, perhaps this intensity is one of the reasons behind Borg's caution. The "Ice Man" seemed as laid-back as ever over his young son's passion.
"He's doing pretty good actually," he told Cash, who was himself a tennis dad to son Jett. "The most important thing is that he enjoys tennis and he likes to play. He's winning, he's losing."
Though it's too early to assess, Swedish Tennis Association U-14 coach Frederick Hornell believes Leo is one of the top 10 in his age group.
"He's an interesting player for sure. His game has improved a lot over the last year. We will check him out a little bit more in the summer," said Hornell, referring to selection for the association's U-14 training camp in October.
While being the son of one of the all-time greatest players has its pros and cons, Hornell said that Borg keeps a "low profile" at tournaments.
"To have a father who's almost a legend in tennis, that can put some pressure on [Leo]. But the positive thing is that he has a lot of experience and can help him out with his game.
"I'm sure there's potential and possibilities for him to become a good player, if he wants to. At this age, it has to be fun."