The Dane moved to the Stadium of Light this summer on a season-long loan from Arsenal but has so far failed to have a major impact and has managed only two goals.
Bendtner is doubt for Sunday's crunch clash against Blackburn with a groin injury, but the manager is determined to help the 23-year-old realise his potential, and said: "I think that is paramount. He has a lot of natural talent. He wasn't always in the starting line-up at Arsenal. They have allowed him to come up here and now it's an important time for him."
He added: "This season is one where he can come through, he can score some goals. He obviously might have to adapt to a different style of play in the sense that Arsenal have the ball all the time in the vast majority of matches, even against the very best teams.
"With respect, we might not have it as often so you have to allow him to adjust but essentially he has to try to get some goals."
Midfielder Craig Gardner, a summer signing from Birmingham, has also been a disappointment thus far and was in and out of the team under Bruce.
He is a player O'Neill knows well from his Aston Villa days and the Northern Irishman is hoping Gardner and other players who have been on the sidelines can begin to play a full part.
O'Neill said: "I sold Craig to Birmingham but the players who were keeping Craig out of the team were all England internationals, so it was going to be hard for Craig to play, and he wanted to play first-team football.
"But he is genuinely a terrific lad and he can score a goal, and I'm sure he's relishing the challenge ahead of him again. That would go for a couple of other players who also played (on Thursday) in the reserves. Titus Bramble, for example, and David Vaughan, for them just getting an opportunity to get a bit more football in was good.
"And it's important for me to have as many players available as possible. We have one or two that have struggled with injuries but hopefully in the near future we can get these people on the pitch."
Source: PA
Source: PA