Zabaleta believes they’ve lacked scoring goals compared to last season, which they had 21 goals more at this stage.
Manchester City were held to a 1-1 draw at the Etihad and the result puts them seven points behind league leaders Chelsea.
Sergio Aguero hasn’t found the net in five games after his return from injury, Edin Dzeko's last goal was in September 2014 and Jovetic's was on New Year's Day.
With the Citizens' last win in the Premier League being on the New Year's Day, the City right-back thinks they’ve not been “clinical” enough in the 2014-15 campaign.
“Last season we were more clinical and scoring goals in different ways. This season it seems it’s been a bit hard and we’ve not been clinical enough,” Zabaleta is quoted saying by the Mirror.
“At the moment I think that’s the big difference between last season and this season, not just because this team is relaxed or anything like that.
“I don’t think this squad is relaxed the season after we won the league. It’s just because it’s really hard. Every season it’s really hard to win.
“Sometimes you can understand there are a lot of teams that are playing better than ourselves.
“At the moment Chelsea are being more consistent than us and we’ve been struggling a bit with injuries to the important players.”