Bent left for Aston Villa a year ago and O'Neill has since replaced Steve Bruce in charge of the Black Cats.
Wickham, an £8.1million signing by Bruce from Ipswich last summer, has so far been restricted by a knee injury to five starts - and one goal - this season.
And the 18-year-old is keen not to become a forgotten man if Sunderland, as seems likely, dip into the transfer market for another striker during January.
"Some boys have gone for big-money moves at my age and got lost in the game," he told The Journal.
"I do not want to be one of those where in a few years' time people are asking, 'Where is he now?'
"It is all about keeping your head right, training right and being sensible off the pitch, keeping everything in order.
"I think I have a manager who is going to make sure I do that.
"He has made it quite clear the boys have to be right.
"What is working off the pitch is showing in how well we are doing on the pitch. He has brought something to the team which is unique and that is why the boys are doing well."
Wickham believes he is capable of making an impression during the remainder of the season.
"I feel I am ready to step up now," he added.
"If I get a run of games and I score a goal - if you get one then you get another and another and another. It boils down to when I can earn my place back in the team.
"Hopefully when that happens I can score the goals we need."
