Per John Duerden of ESPN FC, Juve chairman Andrea Agnelli responded to K-League president Oh Kwon-Gap's initial call for an apology by saying Ronaldo was told by club medical staff "to rest due to muscle fatigue after the Nanjing game [against Inter Milan] which was only 48 hours before."
Organisers of the exhibition match at the Seoul World Cup Stadium said the Portugal international was contracted to play at least 45 minutes, but instead he remained on the bench throughout.
After Agnelli's explanation, the K-League again demanded an apology, per Reuters (h/t the Guardian):
"K League clearly registers our profound indignation and disappointment to Juventus’ irresponsible behaviour and manners, and we strongly urge Juventus to offer a sincere apology and explain the reason for Ronaldo’s no-show.
"The key point ... is that Ronaldo did not play even for a minute, contrary to the contract guarantee that he would play for at least 45 minutes. However, Juventus’s reply did not offer any apology nor did it explain what exactly happened that day."
Some of the fans in attendance at the 66,000-seater stadium have threatened to take legal action following Ronaldo's no-show:
Juve's 3-3 draw with the K-League All-Stars was their third match of pre-season following a 1-1 draw with Inter, which they won on penalties, and a 3-2 defeat to Tottenham Hotspur.
Ronaldo, 34, is Juventus' key player and it is understandable the Serie A champions did not want to risk him just two days on from his 90-minute, goalscoring showing against Inter.
Juve's 2019-20 season gets underway on August 24, when they take on Parma in the Italian top flight.
In the interim, the Old Lady face Atletico Madrid in the International Champions Cup at Stockholm's Friends Arena on August 10.
It will be crucial that Ronaldo is fit and firing by the start of the new season, when Juve will be aiming to win a ninth consecutive league title.
With new manager Maurizio Sarri at the helm, the Old Lady will also be looking to win the UEFA Champions League for the first time since 1996, something Ronaldo is confident his side can achieve:
Juve have added further quality to an already strong squad this summer in the shape of Aaron Ramsey, Adrien Rabiot and Matthijs de Ligt, and they will be a force to be reckoned with in Europe in 2019-20.