City have failed to win any of their last three games in all competitions and have lost twice this week to West Ham and Newcastle United.
Those defeats have seen Manuel Pellegrini's side slip further behind Chelsea in the Premier League and fail in the defence of their League Cup crown.
Jovetic played the full 90 minutes in Wednesday's 2-0 reverse and again drew a blank, with his last goals coming in the 3-1 win over Liverpool in August.
"We need to be more determined and we need to score goals," he said. "Because we are a team that scores more goals than everybody and when we don't score we have problems.
"It happened last night [Wednesday]. I hope the next game we will score again.
"Unfortunately we didn't make it but now we must forget, recover well and think about the next game."
City have won the last three derbies against Manchester United, averaging three goals a game in those matches.
