Nuno was keen to stress that the Greek owner’s actions were down to «confusion» over the use of striker Awoniyi.
The Nigerian emerged from the bench following Leicester’s late equaliser, charged with finding a winner.
He showed his desperation to score when he slid in at the backpost in the hope of connecting with an Anthony Elanga cross, only to collide with the goalpost.
The 27-year-old was down for several minutes as he received treatment, inadvertently halting any hopes Forest had of quickly restoring their lead.
Awoniyi signalled he was fine to continue, persuading Nuno to leave him on the pitch, instead bringing on Jota Silva for midfielder Elliot Anderson.
But the forward remained in discomfort, which Nuno said infuriated owner Marinakis.
«It [the conversation with Marinakis] was due to the situation and the confusion over the substitution of [Taiwo Awoniyi],» Nuno said.
«We made a [different] sub and after that we played with one man less so that frustrates everyone.
«When a player is down, you get information that he is OK to continue, then we make a sub and it turns out he can’t continue. We are all frustrated with that.
«Football is emotions. It’s difficult to control [and] especially when we had so much expectation and the fans were incredible.»
Pushed on whether he was comfortable with being approached in so public a manner by Marinakis, Nuno again praised the owner.
«It is because of the owner and his passion that we are growing as a club. He pushes us. He wants us to be better,» Nuno added.
«It is his passion and desire to be a big club — 30,000 people felt the same today. For sure, many of them would go on the pitch and shake us down.
«Us as a club, we owe a lot to the Marinakis family.»
