Como were beaten 2-1 on the night as Assane Diao canceled out Randal Kolo Muani's opener before the Frenchman scored the winner from the spot.
“I am satisfied with the performance, we had 60 very strong minutes and did not deserve to lose the game,” Cesc told Sky Italia.
“There were improvements from the matches against Milan and Atalanta, as we were able to control the situation, but there are some things you cannot battle against and that makes it difficult.
“I am referring to the penalty incident, rather than wait for you to ask me.”
Before Juve's winning penalty, Fede Gatti escaped a handball incident at the other end of the pitch.
Cesc said, “There is no other interpretation, it is a very clear penalty. Douvikas is controlling that with his chest and without the touch from the hand, he is going clear on goal, an incredible opportunity to win the game.
“Now you go home with zero points, you end up feeling stupid, but today I cannot stay silent. It happened in January against Lazio with Gigot’s very strong tackle on Nico Paz – not saying it’s a red, but certainly a yellow verging on orange – not even a free kick and we lost the player for three matches to injury.
“A very clear foul in midfield against Milan, nothing given, Milan get a corner and score to win. Como-Udinese, Goldaniga does not touch the player and gets a second yellow to be sent off. Against Roma there was Pellegrini who should’ve had a second yellow card, nothing given,” listed Fabregas.
“So today I say enough, because I have to defend Como. I am not talking for myself, I am defending the club and this city. I know it is a small place, there aren’t many of us, but I have to stand up for Como.
“I understand the referee does not see this incident with Gatti, but when the VAR evaluates that footage and doesn’t say anything, that is where I have doubts in my mind.”