The fireworks and euphoria that greeted Ronaldo's gala unveiling in January were in sharp contrast to the close of Al Nassr's season, when the Portuguese sat out a 3-0 win against Al Fateh late on Wednesday.
Despite signing the five-time Ballon d'Or-winner in a two-and-a-half-year deal said to total 400 million euros ($428 million), Al Nassr finished second in the Saudi Pro League without any silverware, although it qualified for the Asian Champions League as a consolation.
"I expected to win something this year, but we didn't," Ronaldo said in an interview broadcast on the Saudi Pro League's social media channels. "But next year I am really positive and confident that things will change, and we go in a better way."
Ronaldo scored 14 goals in his 16 games, racking up 1,701 minutes. But it was a "disappointing season" for Al Nassr, the favorite team of some senior Saudi royals, said Al Riyadiah newspaper's editor-in-chief Moqbel Al-Zabni.
"They needed at least one championship," he said.
Fan frustrations aside, however, the 38-year-old remains a marketing coup for Saudi soccer and the wider country, which is attempting to reinvent itself as a magnet for tourism and foreign investment.
Saudi Arabia is trying to land a "huge" deal for Ronaldo's ex-La Liga sparring partner Lionel Messi, the World Cup-winning Argentine icon.
'I will continue here' Reports have linked a string of other big names to the Saudi Pro League thanks to the riches of the Public Investment Fund, the sovereign wealth vehicle behind LIV Golf and the purchase of Premier League club Newcastle United, as well as Ronaldo's signing.
Saudi Arabia is also considering bidding for the World Cup, following in the footsteps of its neighbor Qatar, and has already explored joining forces with Egypt and Greece to present a tri-continental option.
Saudi Arabia's lavish spending on sports is often criticized as "sportswashing" -- an attempt to shift the focus from its record on human rights.
The conservative monarchy executed 81 people in a single day last year, outlaws homosexuality and triggered international condemnation when journalist Jamal Khashoggi was murdered in the Saudi consulate in Istanbul in 2018.
Ronaldo has said little in public since arriving in Riyadh with his model girlfriend Georgina Rodriguez -- a highly bankable influencer with 49.5 million Instagram followers -- and five children.
But in an official interview released on Thursday, he pledged to stay in Saudi next year, and backed the Saudi league to eventually become one of the world's top five.
"We have very good teams, very good Arab players. But they need to improve a little bit more the infrastructure. Even the referees, the VAR system, should be a little quicker," he said. "I think other small things they need to improve. But I am happy here, I want to continue here, I will continue here."
'Fans want championships.' Although it quickly became clear that the veteran player could not win games single-handed, Saudi football has never enjoyed such attention.
Al Nassr's Twitter followers have jumped from 800,000 to more than four million, and swelled from two million to 14 million-plus on Instagram.
Female fans, barred from soccer stadiums until just a few years ago, have become a common sight, while Ronaldo has also drawn many families with children.
"Saudi football has become the talk of most international news agencies and media," Saudi writer Musaed Al-Abdali wrote in his column for Al Riyadiah.
Egyptian sports analyst Ahmed Afify said Ronaldo could not be blamed for the trophy-less season, pointing to injuries to other players including Colombian goalkeeper David Ospina.
"He (Ronaldo) showed great commitment and did not act like a big star towards his teammates," Afify said.
However, some supporters were not impressed with what they saw of Ronaldo, who sometimes appeared anonymous.
After Al Nassr drew against a modest Al Khaleej outfit two weeks ago, fan Mubarak Al-Shehri lashed out at Ronaldo's "bad and incomprehensible performance".
Another fan, Ibrahim Al-Suwailem, wearing the traditional Saudi white robes, questioned the decision to buy Ronaldo.
"Ronaldo alone is not enough," he said, adding: "Is it worth this huge amount? It's a deal for publicity, and the fans want championships at the end of the day."
© Agence France-Presse