Kewell left Leeds for Liverpool in the summer, with Viduka calling him a loner.
But Kewell said in The Sun: “Some things, even a personality clash, are better left behind dressing room doors.
“Mark said a few choice words about me. As for me, personally, I have no problem with him.
“I know what a good player he is and I appreciate him for that. But if he wants to say things behind my back, then I am not going to enter into a stand-up argument with him.
“I do look on loyalty as being very important and my two best mates are still Michael Bridges from Leeds United and a mate from Sydney who now lives in England.
“But football, scoring goals, is still the greatest rush. It is one of the greatest feelings ever, I can’t explain it.
“There are days when things are not going too well and you would rather be left alone, but I would be surprised if anyone said they didn’t like the attention that football brings.
"Away from football, I do find it quite embarrassing.”