The attacking midfielder has developed into one of Liverpool's star players since joining the club from Inter in January 2013 and has been linked with clubs such as Barcelona and Real Madrid in recent months following his sublime performances at Anfield.
The 23-year-old opted against a move away from Liverpool ahead of the 2015-16 campaign, but his compatriot expects him to leave if they again fail to qualify for Europe's elite club competition.
"Coutinho made the choice to stay at Liverpool without Champions League football this season. I don't think he will make that choice again," David Luiz was quoted as telling the Sunday Express.
"The best need to be playing with the best. Coutinho is the best midfielder in England right now. That is great for him, but when you play at that level the big clubs will notice you.
"If Liverpool don't qualify this season for the Champions League, I am sure he will be the most in-demand player in Europe next summer."
Coutinho has a contract with Liverpool until June 2020.