Saturday's 3-0 home victory over West Ham established a six-point gap between the Black Cats and the Barclays Premier League relegation zone despite O'Neill having to contend with a lengthy injury list.
But the fact that it was achieved without a single specialist full-back illustrated the club's need for reinforcements, and the process of strengthening the squad was continuing on Sunday with Al Hilal defender Kader Mangane due on Wearside in an attempt to tie up a loan move.
Nevertheless, as O'Neill prepared to attempt to lure new recruits to the Stadium of Light, he did so with a fresh spring in his step.
He said: "We are trying our best, obviously, to try to bolster the squad, which will be very, very important if we can do.
"But again, the great thing about the win, which is I suppose reminiscent of last year, only for 24 hours or 48 hours it takes a little bit of pressure off. It gives you a bit of respite and gives you a chance to look again."