Courtois was the first to copy Pique in reference to Costa, after the player remained a Chelsea player beyond the Spanish summer transfer window deadline on Friday night.
However, Chelsea rebuffed that move as they sought the Premier League title, and though it was meant to go through this summer, a new 100 per cent tax on foreign transfers caused the deal to collapse.
Costa was actively hunting for a way out at Chelsea after Antonio Conte informed him at the end of last season that he had no future with the champions.
The unsettled striker made it known during Sportsmail's exclusive interview last month that he wishes to re-join Atletico Madrid, but they are under a transfer embargo until January meaning Costa would be unable to play for Diego Simeone's team until the turn of the year.
Monaco reportedly make their stance clear on Liverpool's £74million approach
Monaco had a hard transfer window as they lost the services of Kylian Mbappe , Bernardo Silva, Benjamin Mendy and Tiemoue Bakayoko.
The situation gets messier still as Costa has legal proceedings open against Chelsea for "discrimination" as explained by his lawyer in a statement to the news agency EFE.
Since reportedly sending the striker a text message that he was not a part of his plans, relations between Costa and Conte broke down.
Meanwhile, Costa has been encouraged to return to fitness by Spain team-mate Sergio Ramos.
'I'm now with a team that have made a massive financial commitment for a Real Madrid substitute, ' said the 24-year-old. That is why I have to make a big impact and really make my presence felt.
"It's true that they're sloppy tactically and they give you chances because they slip up, but it's a different kind of football".
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