Roberto Mancini admits that Edin Dzeko is not satisfied with his role as Manchester City's "super sub", but says he hopes his forwards continue to perform at their current high level.
City's Bosnian striker scored a late winning goal as the defending Premier League champions beat Tottenham Hotspur 2-1 on Sunday to maintain pressure on early season leaders Manchester United.
Dzeko has now scored 11 league goals coming off the bench and, with Mario Balotelli not even named in City's 18-man squad, his lack of first-team starts indicates the champions' remarkable strength in depth.
"Edin is not happy," said Mancini. "A player who is happy on the bench does not exist.
"We had three important strikers today. Last year, we won the championship because of goals from our strikers. Today, we missed some goals from them, but hopefully they will continue to score.
"The Premier League season is long and difficult - there are a lot of teams who can fight for the title. Tottenham can come back and fight for it, as can Arsenal.
"We made some mistakes in the Champions League, but in football you can never say never."
Mancini's assistant David Platt expanded on the role of Dzeko, who previously scored two goals to help City come from behind and win at West Bromwich Albion last month.
"After West Brom, I said then, we can only pick 11 players but hopefully we bring on the right substitutes," said Platt.
"We have a lot of players who could play for most Premier League teams, but we can pick only 11 and Edin is one of those players who can either start or be a substitute.
"We needed an injection - a bit more height, someone to hold the ball up up there, also someone to be a platform.
"Edin has scored some important goals, he's a valued member of our squad. We haven't tagged him 'super sub'."