One more win would see them reach the traditional 40-point safety benchmark - and Vaughan reckons victory at Aston Villa would effectively put an end to any lingering relegation fears.
Vaughan told the Evening Chronicle: "Do I think one more win will keep us up? Yes, I think it almost certainly will.
"If we beat Aston Villa on Monday there will be a six-point gap between us, there will be a gap between us and Wigan and maybe one or two others.
"So reaching 40 points will be significant if we can do it.
"It will make it difficult for other teams to catch us with games running out - especially as our goal difference is good compared to a lot of other teams."