O'Neill feels Agbonlahor should cash in against opposition such as the bottom-of-the-table Rams.
He creates a lot of problems for opposition defences. He gets behind them and often they do not where he is at times," said O'Neill.
The England Under-21 international striker said: "No matter who we are playing we are capable of testing any team as we did against Manchester United.
"We always look good going forward. Playing at home we have generally done well like we did against Chelsea.
"Everyone is at the top of their game and we are confident of doing well."