Wolves hitman Steven Fletcher handed in a transfer request and did not feature in the defeat at Leeds, amid rumours he will soon be joining Sunderland in a ?15million deal. And O'Neill maintains the sooner new men can come in, the better.
"We would have liked to have had some players in before the Arsenal game, but that did not happen," he said. "We have a lot of spirit about us, but lack quality in some positions. We need some better attacking options."
O'Neill added: "It has been slow, perhaps people's attentions have been elsewhere with a fantastic Olympic Games, but maybe now there might be that bit of movement."
The Black Cats battled to a goalless draw on the opening day of the new Barclays Premier League season at Arsenal, but spent most of the second half defending deep.
O'Neill was able to bring in veteran forward Louis Saha, on a free after being released by Tottenham, in time to face the Gunners, while defender Carlos Cuellar made his debut after signing from Aston Villa.
Sunderland have seen a ?12million bid rejected for Scottish forward Fletcher, but are expected to go back with improved terms.
"Fletcher has been one of the players mentioned, but we need to strengthen because we need some help," said O'Neill.
Defender Kieran Richardson threw his shirt into the travelling supporters after the final whistle at Arsenal and O'Neill admitted the former Manchester United man had been keen on a move back to London, with QPR reportedly in for the 27-year-old former West Ham youngster.
"No one has come in and made an offer. That, though, does not mean there is nothing happening, I just don't know," O'Neill said. "But if he performs like he did against Arsenal, I would like to keep him."
Source: PA
Source: PA