Simone Inzaghi feels Inter were shown a "lack of respect" after a VAR review decided to allow Filip Kostic's controversial winner in a 1-0 defeat to Juventus on Sunday.
Kostic lashed home the decisive goal after 23 minutes at San Siro, though a lengthy VAR check was needed to judge whether the ball had taken a touch off Adrien Rabiot's arm in the build-up.
The goal stood, and Juve went on to earn victory as the Bianconeri moved within nine points of third-placed Inter and seven points of the Champions League places.
It was Inter's third defeat from their last four Serie A outings, and Inzaghi was left fuming by the decision to allow Juve's winner to stand, though he was also proud of the way his players responded to what he felt was an injustice.
"The boys were good in the second half," Inzaghi told reporters in his post-match news conference. "At the end of the first half they saw what we suffered and it's unacceptable.
"Honestly to talk about football it's difficult for me, it was even difficult for me to talk to the team after the first half. We tried to remedy it, despite an unacceptable goal.
"There shouldn't be nervousness, but as far as the second half is concerned, the boys managed to keep calm to try to draw a match clearly spoiled by what happened.
Defeat at San Siro.#InterJuventus 0-1 (FT)#ForzaInter @eBay_Italia pic.twitter.com/UX61lqBHz2— Inter (@Inter_en) March 19, 2023
"What happened is too serious. It's a lack of respect, and when I feel there are no images [of the incident], it's all the more so. It took four minutes.
"It's an irregular goal that penalises us, in a delicate moment, a delicate match. Conceding a goal like this is unacceptable."
When asked if he had spoken to referee Daniele Chiffi in hopes of clarification, Inzaghi replied: "No, it was so clear that it didn't seem right to me. There are such clear and glaring images."
The Nerazzurri have now won just one of their last five in all competitions, scoring just three goals across those games.
This latest blunt attacking display saw them muster just three shots on target despite having 69.4 per cent possession.
With the international break meaning Inter do not play again until April 1, Inzaghi is confident his players can use the league's pause to halt their poor run and enjoy a strong end to the season, explaining: "With all the matches we're going to play, I need everyone.
"You played a match that you shouldn't have played and you lost. The team would have deserved another result but this is football."