Sunday's 1-0 loss at Sunderland was their fourth defeat in six Premier League away games this season, as City were frustrated by a resolute hosts' defence.
While Zabaleta knows the race for top spot is likely to go down to the wire in what is the most unpredictable league campaign for years, he feels City's form on the road could prove a major hurdle to overcome.
"There is a long way to go and we have too many games to the end, but when you lose points like that it will be really difficult to fight for the title," he told the Manchester Evening News.
"When you have a defeat like this you want to play as quickly as you can, but we now go into an international break, and then we will face Spurs at home, which will be a crucial game for us."
Zabaleta, Jesus Navas and Edin Dzeko were all introduced in the second half at the Stadium of Light as City searched for an equaliser, but to no avail.
However, the Argentina international is more concerned about the club's inability to keep a clean sheet than their forward line.
"It is true we cannot keep a clean sheet, and when you play away, you must defend much better, and try not to concede goals," he continued.
"It's not happening, every time we play away.
"We need to focus on what we are doing at the moment, and improve our performances away."
