Silva, 30, lost the captaincy following Brazil's embarrassing finish to their hosting of the World Cup, as they lost 7-1 to Germany in the semi-finals before a 3-0 rout in the third-place play-off at the hands of the Netherlands.
Dunga was appointed Brazil coach for a second time, and he moved to hand attacker Neymar the armband, leaving the PSG central defender's position in jeopardy.
Silva has not played for Brazil since the World Cup, but he said he is keen to try and earn his spot under the new boss, who has commandeered Brazil to five straight clean-sheet wins.
"Sincerely, I didn't expect this," Silva said, ahead of Brazil's friendly with Austria on Tuesday.
"But I think we must be prepared for everything, somehow, even if I thought I was going to come and play.
"I have to be ready to be on the bench also.
"We have quality players, like David Luiz and Miranda, so I knew that it was going to be hard, but I didn't expect to be dropped.
"But it's part of football and I'm ready to fight for my place back."
Defender Filipe Luis had glowing words for Dunga, who has significantly altered Brazil's fortunes since the World Cup.
The Chelsea stopper was drafted into the national set-up by Dunga, and has played every minute under him in helping strengthen Brazil's defence.
Filipe Luis said the players are happy with Dunga's training methods.
"I talked a lot with my team-mates. We are delighted with this type of training because the intensity required is always very high, we are always on training and on the game," he said.
"So this type of training helps us to improve a lot and work on the way that we play with our team mates.
"You start to know your team-mates better on the field. So, we are very happy because they are requiring the maximum from us."
