Brazil and France have advanced to the round of 16 and if Brazil top their group as expected, the earliest stage that both nations could meet is in the final.
"He's a top player and he has done a lot of good things at Arsenal this year," Saliba said.
"I hope he has a great performance [at the World Cup] but as of today, I hope they go out as soon as possible."
The reigning world champions face Poland in the knockout stages of the World Cup on Sunday.
France are back in the round of 16 of a major tournament after reaching that stage at last year's European Championship and memories of their shock elimination by Switzerland will still be fresh.
Les Bleus were 3-1 up against the Swiss but conceded two goals in the last 10 minutes before going out on penalties.
"I think we were too relaxed against Switzerland," Antoine Griezmann told a news conference on Friday.
"When we were 3-1 up we thought it was over. In big competitions you realise that there are no easy opponents, it's going to be the same against Poland. Nothing is guaranteed, we will need to be focused from the first to the last second.
"We have to bear in mind that nothing can be taken for granted."
France have not been awarded a penalty at this World Cup yet and Griezmann would not say who would be taking them should the opportunity present itself at the Al Thumama stadium.
"Who takes penalties is very clear for us. But I will not give [Wojciech] Szczesny any info, he's already good enough. Let's keep it a surprise," Griezmann added.
"We're going to work on this today, or more likely tomorrow because today's training session is open to the media," he added with a smile.
Information from Reuters was included in this report.