O'Neill admitted that he thought his team would have too much for the visitors despite the appointment of Harry Redknapp, and was "frustrated" to see them held to a 0-0 draw.
"I was hoping we could win the game. I know that Queens Park Rangers would be buoyed obviously by the appointment of Harry Redknapp," he said.
"But I thought we could create enough tonight to win the game.
"This has been a tough old season for us obviously. I think there were plenty expecting that too. Outside the top seven or eight teams you can either be looking up the league table or over your shoulder.
"It was a rather frustrating evening, I think frustration would sum it up."
Lee Cattermole, who shook off a knee injury to start, departed with just seven minutes played having damaged the other knee in a 50-50 challenge with Samba Diakite.
O'Neill confirmed: "It was his other knee that he hurt, funnily enough, in the block challenge and as we speak now, he's in a lot of pain, so that would be a blow to us if that was the case.
"It seemed as if it was the same knee - I thought immediately that was the case - but it's not, it's his other knee."