Flick's tactical approach, featuring an extremely high defensive line, also seemed ripe for Mbappe and Vinicius to pillage with their pace.
Swedish prosecutors on Tuesday confirmed an investigation had been launched -- without naming Mbappe -- following an alleged rape at a plush Stockholm hotel on October 10.
Los Blancos take on their rivals without the French forward, ruled out for three weeks with a hamstring injury.
The format may be new, but few would bet against the winner staying the same.
The 2018 World Cup winner almost joined Caen as a teenager before eventually signing for Monaco.
The France captain, to his credit, was sublime in creating the goal that beat Austria 1-0, but his failure to score at a Euros will weigh heavily on a player who has found the net 12 times at World Cups, including a hat-trick in the 2022 final.
"The Euros is very important in our careers, but we are citizens first and foremost and I don't think we can be disconnected from the world around us," said Mbappe.
Mbappe, 25, verbally agreed to move to Real in February and then announced in May he would leave PSG at the end of the season.
PSG's decision to withhold Mbappe's salary is related to an agreement between the two parties made last year, at the start of the season, when the player accepted to waive part of a bonus due to him, the source said.
The only time PSG have previously appeared in the biggest match in club football turned out to be a depressingly flat occasion, with the French side losing 1-0 to Bayern Munich behind closed doors in Lisbon in 2020, at the height of the pandemic.
Luis Enrique's team would have sealed the title later on Wednesday if second-placed Monaco had failed to beat Lille at home, but the principality side prevailed 1-0 courtesy of Youssouf Fofana's second-half strike.
Mbappe, who is set to leave PSG in the summer with Real Madrid as the biggest favourite to sign him, told reporters that his future is not in his mind and that his focus is totally on bringing glory to the French capital.
Paris Saint-Germain overcame a controversial first-half sending-off to win 2-0 away to bitter rivals Marseille in Ligue 1 on Sunday, with Portuguese duo Vitinha and Goncalo Ramos scoring their goals.
The Euro 2024 favourites were left reeling after conceding just eight seconds into their game against Germany in Lyon last weekend, which they went on to lose 2-0.
"It is very difficult from a psychological and physical viewpoint to take part in two competitions like that one after the other, in the summer, without having any holiday," Deschamps admitted on Thursday.
"It's very simple, sooner or later, when it happens, we have to get used to playing without Kylian," Luis Enrique told the post-match press conference.
"Mbappe has communicated his decision to PSG but the terms of his exit are yet to be fully agreed. An official announcement is expected once the situation is finalised in the next few months," the report said.
"I was pleased with the whole match, I think my team is competitive each time and today was no exception," said PSG coach Luis Enrique.
Mbappe's contract with the Ligue 1 champions runs out at the end of June and he is free to sign an agreement to join a new club for next season.
