According to Brazilian media reports, the defense minister was fired after he protested against Bolsonaro's attempts to strengthen his control over the military.
Azevedo e Silva is not the only Brazilian minister replaced during the week.
Six ministers have been replaced - including Foreign Minister Ernesto Araujo, who has been widely criticized for making it difficult for Brazil to secure covid-19 vaccine deliveries.
The country is hard hit by the corona
At the same time, the spread of infection in Brazil remains high.
Brazil's healthcare is under very high pressure with full intensive care units in many of the country's states.
In the past week, an average of 2,595 Brazilians have died per day from covid-19 and the country, which has three percent of the earth's population, currently accounts for a third of the corona - related deaths in the world.