Having invested heavily again this summer, and brought in Manuel Pellegrini to replace Roberto Mancini in the dug-out, many installed City as pre-season title favourites.
Four defeats in six away games has seen some pundits rapidly revise those predictions, but former City midfielder Hamann still believes they have enough talent to turn it round.
"They have to keep their home form and they have to start winning away games," Hamann told Sky Sports News.
"It has been very disappointing to watch them in games that you did not expect them to struggle in.
"Probably at Aston Villa, they were a little hard done by by the referee. They were well on top in the first half and probably should have won the game but I don't think there were too many complaints at the end.
"But at Sunderland and Cardiff, they also lost and they have been beaten four times away from home this year. You would think they can probably only afford to lose two, maybe three, more if they want to win the league.
"For me, they are still the most likely Premier League champions, but they have to start improving their away form. If they don't do that, once you get six points behind the team at the top - and the way Arsenal is going now - it could be very hard to claw them back."
Tottenham have also struggled for consistency under Andre Villas-Boas - and while they may not be title challengers, Hamann still believes they can still challenge for a top-four finish.
"As for Spurs, they do not score enough goals," Hamann added. "I still think they have every chance of finishing in the top four because they have a very talented squad.
"If you look at their bench, it is better than most other teams apart from maybe Manchester City. They have a host of players there that are top international players.
"If they were to get beat at City on Sunday - which I think they will do - they get further and further behind and you just wonder, once you are six or seven points behind the top-four spots, it is not that easy to make up."
Manchester City against Tottenham is the first part of a Super Sunday double header - live coverage from the Etihad starts from 12.30pm on Sky Sports 1 HD. That's followed by Cardiff City v Manchester United from 3.30pm.