Former Swiss national team goalkeeper Yann Sommer is also part of the consortium that is buying 90 percent of the club.
The group is reportedly paying 40 million euros, almost 450 million kronor, to former owner Paulo Lopo, who in turn bought Estrela in 2020 for 72,000 euros.
Müller and Hummels won World Cup gold with Germany in 2014 and Fernandez with France four years later.
Estrela, which was close to bankruptcy in 2011, finished 15th in the 18-team Portuguese top division last season and just signed a new contract.
Amadora is located ten miles northwest of Lisbon.
