Commons criticised his teammate's performance in the match, which came just hours after he returned to Glasgow from the Africa Cup of Nations.
The Nigerian defender told the Daily Record: "Kris is a great friend. We've been chatting and laughing. But I know how he felt after the Juve game. Sometimes when you lose, it brings out another side of you.
"I know when I don't feel happy about something, it's good to say so. I understand that and just take everything the way it comes - and Kris has since apologised. However, he did not express things in the proper way. If Kris had been calm when he spoke, he wouldn't have said what he said. But I understand.
"What he did do was make me a better player and gave me a challenge. Next time I will stand up for myself and stand up for the team. That's what he was telling me. I know what he was saying better than people who were not in the dressing-room."
The Scottish champions will look to overturn a three-goal deficit when they play the second leg of their tie against the Italians on Wednesday.