The match on Thursday in Riyadh is set to pit Messi's Paris Saint-Germain against a select side made up of players from Ronaldo's new club Al Nassr and their Saudi rivals Al Hilal.
It will mark the first time Ronaldo has played any football in the kingdom since signing a contract with Al Nassr that runs until 2025 and is worth more than 200 million euros ($214 million), according to sources close to the club.
The five-time Ballon d'Or winner is scheduled to make his Saudi Pro League debut for Al Nassr on Sunday.
To promote Thursday's friendly, Turki al-Sheikh, an advisor at the Royal Court and head of Saudi Arabia's General Entertainment Authority, announced a charity auction for a special ticket that would come with perks like photo opportunities with players and access to the locker rooms.
Bidding started at 1 million Saudi riyals ($266,000) and the auction closed at 11:30 pm local time on Tuesday.
Sheikh then announced on Twitter the winning bid of 10 million riyals ($2.6 million) had come from Mushref al-Ghamdi.
"Congratulations, you deserve it, and may God reward you with good," Sheikh said.
The proceeds from the auction are due to go to the national charity campaign known as Ehsan.
Besides Messi, PSG stars expected to play on Thursday include France striker Kylian Mbappe and Achraf Hakimi, who last year in Qatar helped make Morocco the first Arab and African team to reach the World Cup semi-finals.
The Saudi select team includes Salem Al-Dawsari, who scored the winning goal in the Green Falcons' shock defeat of Argentina in the World Cup's group stage.
Ronaldo is expected to receive a combined 400 million euros in the kingdom, including a separate payment for his work as an ambassador for an anticipated World Cup bid for Saudi Arabia, Egypt and Greece, according to sources close to Al Nassr.
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