Balotelli, who made his first start in six matches at the DW Stadium on Wednesday, endured a largely frustrating night but remained focused and gave City the lead with a 69th-minute strike. James Milner added the second three minutes later with a stunning effort to seal the 2-0 win for Roberto Mancini's side.
"Any striker's first league goal is going to be massive in a season. To be fair to Mario, he has not had loads of chances," Barry said. "When you do get them you need to score them. He has taken a chance with his start here. It could be good for Mario. Hopefully he can go on a run now."
He went on: "Mario is not going to lack in confidence if he misses two or three. He'll keep trying the same things. Hopefully his goal will give him a bit more confidence and he can improve from there."
Balotelli was dropped for the match against Tottenham earlier this month and was then kept out by a back injury.
Speculation that the 22-year-old will leave Man City during January's transfer window has continued despite Mancini's denials that he is not looking to move him on.
Barry believes Balotelli wants to stay at the Etihad Stadium and hopes the controversial striker will quickly start to add to his goal tally.
"I think he is happy," Barry said. "If you see him day to day then you'd see no reason for him not to be.
"Obviously he has probably not played as much as he would have liked but he has kept his head as well as anyone else who isn't getting chances.
"He scored some massive goals last season and if he can repeat that this season it'll be good for us."
Source: PA