The Black Cats will head into a final day showdown with Chelsea on Sunday knowing their Premier League status hangs in the balance.
They are one of four teams desperately hoping to avoid slipping into the Championship on a tension-filled weekend.
Two of those sides must go, though, with Middlesbrough and Newcastle currently sitting just behind Hull City and Sunderland.
Sbragia is confident his side can take something from a home date with Chelsea, but admits morale has been shaken by a 3-1 reversal at Portsmouth last time out.
"I do believe we will stay up. We could always beat Chelsea. There is always the belief we can do it," he said.
"They might have their minds on the FA Cup final. I don't know what team they will pick but we know what we have to do.
"The players are down but you just hope they have that ambition to stay in the Premiership. The players should want to do that.
"They were in that mood last night (against Pompey on Monday) but they need to be stronger against Chelsea."
TestingWhile Sunderland are planning for a visit from the high-flying Blues, Sbragia believes all of their relegation rivals face tests equally as tough this weekend.
"We have got a difficult game. Hull have a difficult game against Manchester United and Newcastle have to go to Villa. None of them are easy games and if you win one of those you deserve to stay up," he said.
"A draw may be good enough but it is going to be a difficult up-and-down Sunday for us. We cannot afford to lose it, that's for sure."
Sbragia also claims to hold no fear regarding the security of his position at the Stadium of Light, insisting he will not let speculation affect his preparations.
He said: "You could win it and be sacked, you could lose it and be sacked. I could be knighted. Who knows?
"I just know I will give it my all and I hope the players do the same."