Onuoha was part of the City side that lost 1-0 to rivals Manchester United at Eastlands on Saturday, a defeat that leaves his side languishing in 14th place, with one game left to play.
City have scored only 28 Premiership goals all season, the joint worst record in this season's Premiership campaign alongside relegated Watford.
"We simply haven't scored enough goals," stated Onuoha at the BBC's Your Game event in Manchester.
"If we scored a few more goals we could have finished in a much higher position."
Onuoha was among a group of specially invited guests at the second Your Game 2007 event at the Salford Sports Village.
Your Game is a unique nationwide street football competition, which is designed to provide new opportunities for young people from socially disadvantaged groups in society.
"All the people share the same interests and perhaps if this event wasn't here they might be on the streets doing things they shouldn't be doing," said Onuoha.
"But they are here enjoying the experience and maybe put a more positive spin on their lives.
"Obviously, certain things go on on the street that should not be going on and maybe football can take them away from that, make them focus on channelling their feelings in a more positive way."