And the 26-year-old could have followed Kylian Mbappe, Bernardo Silva, Benjamin Mendy, Fabinho and Tiemoue Bakayoko out of the exit door had negotiations with Atleti - who did secure the services of Sidibe's former team-mate Thomas Lemar before the start of this season - come to fruition.
Sidibe had been a key part of Monaco's campaign last season as they finished runners-up to Paris Saint-Germain, but he suffered a knee injury that was expected to end his season and keep him out of the World Cup. Although he made a quick recovery to return on time to make Didier Deschamps' triumphant France squad, he decided not to leave Monaco right away.
"Atletico Madrid, I do not know at all. We were in good discussions, but it was complicated in relation to my health after the World Cup," he told Telefoot.
"It's a big club in Spain. My objective right now is to be successful with AS Monaco and we will discuss with the club to find the best solution."
Sidibe, who has made 105 appearances for the principality club, has previously been linked to the likes of Manchester United and Barcelona over the last two years, while he is said to have rejected Arsenal for Monaco. After joining in 2016, he signed a contract extension a year later which sees him tied to the club until 2022.
Monaco had a disastrous start to the current season and fell into the relegation zone, but a seven-match unbeaten run under reinstalled head coach Leonardo Jardim has seen the principality side climb out of danger following Thierry Henry's ill-fated stint in charge.