The ex-Napoli boss could not contain his disappointment with his side's draw at home against Cagliari as they failed to convert second-half chances
The Nerazzurri fell one goal behind after 40 minutes of play when Mauricio Pinilla converted a spot kick, but Rolando eventually salvaged a draw for Inter with his strike after the interval.
Nevertheless, Mazzarri was by no means satisfied with his side's draw and believes they were unlucky not to win against a visiting team he was full of praise for.
"We deserved to win this game. We did a good job containing their counterattacks, but unfortunately a number of things went badly as well as far as certain episodes were concerned," Mazzarri said at a press conference.
"Are we a bit inconsistent? It’s not easy to play 90 minutes the same way every time. Especially when you’re up against a Cagliari side that operates so well on the pitch.
"I can only congratulate them on their game. They play some good football and made some really brave choices. They have a number of players who can really hurt you."
Inter sit fifth in Serie A with 40 points from 25 games.