"This is a personal matter and I would not like to talk about it in public," he told Greek radio, before continuing "my representative is in talks with Olympiacos and that is all I can say at this time."
"The only thing I can tell you is that I have not put pen to paper yet," he added.
The 54-year-old tactician could even take control as early as January as, while Olympiacos are five points clear at the top of and on course for their tenth Super League title in 11 years, they are out of Europe after finishing bottom of their Champions League group.
Arsenal through to Europa League last eight despite limp second-leg defeat
The Brazilian league is also in the close season.
Luxemburgo was fired by Real Madrid after just 11 months in charge, having won numerous titles in the Brazilian league.
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