Fabio admits he never expected to be in a relegation fight with Boro when the defender joined the club last summer.
The Brazilian made the step back up from the Championship to the Premier League with Boro, leaving Cardiff City for a move to Teesside in August.
Despite having played at the top level at Manchester United for several years, Fabio has fought for Premier League survival before, with QPR back in 2013.
"I never expected to be in a relegation fight when I came here," he said.
"I saw the team - and I've been in this situation before - and this is one of the best teams I've seen around the relegation zone.
"I'm being totally honest, when I arrived here I never thought we'd be in this position.
"But that's football, when you get a bad run and things go wrong for you. We have to move on with this next game and try to stay in the league."
And Boro's next game comes in the form of a trip to Stamford Bridge to face league leaders Chelsea, who are looking to widen the gap on Tottenham in second place.
But Fabio says Boro will approach the game like any other and is confident that a repeat performance to Sunday's showing against Manchester City is enough to cause problems for any team.
"We have to be cool and calm in the game because Chelsea are a dangerous team," he said.
"You have to have your head in a good place against them. They place like Italian football, very tactical and waiting for your mistakes so we have to be careful.
"We have to play in the same way that we played against Man City, we can hurt any team playing like that.
"With the one-two passing and movement off the ball, it was brilliant. So we have to do that.
"It was maybe one of our best performances under the gaffer and that's what we need to hurt other teams."