The captain was dropped for the s 0-0 draw with Genoa amid reports of a furious argument behind the scenes on Friday.
"There was an argument involving Di Natale, but it wasn't with me. I can tell you that now," revealed the Coach on Sky Sport Italia.
"I couldn't say that yesterday because I didn't want the team to lose concentration. It was nothing to do with me, but there are rules in the locker room and they must be respected.
"I must try to keep the boat on an even keel and ensure the rules are the same for everyone. I will not add any more on the matter."