Under Luciano Spalletti, the 'Nerazzurri' made a stunning start to the 2017-18 Serie A campaign, going unbeaten for 16 matches – including a victory over AC Milan and draws with Napoli and Juventus.
In mid-December Inter were considered part of a three-way tussle for the Scudetto with Napoli and Juve, however, they have since tumbled out of contention.
A run of eight games without a win saw them fall away and, although they have two victories in their last three matches, Inter now sit fifth in the table.
With the top four earning a place in the Champions League, Handanovic says now is the time to overcome their problems and finish on a high.
"If you had asked me in December [if he was happy with the season] I would have said yes," he told 'Corriere dello Sport' ahead of this weekend's clash with Napoli.
"But I would have added that it would be necessary to keep the concentration high until the end of the season.
"Now I'm a little less satisfied. In the league there are ups and downs, and this is definitely a negative moment that we have to overcome.
"I have a goal to achieve, qualifying for the Champions League, and we all have to work for that. We must react."
6 March 2018