Hughes has said that Robinho had left the training camp for personal reasons without the managers permission.
"Robbie left without permission, he felt that he had personal things that he needed to attend to," Hughes told the club's official website.
"He made the decision to leave the camp and go back to Brazil.
"That was not with my permission and the situation at the moment is not really practical to get him back here with time differences and length of flights, so he will be back at the weekend ready to train when we are back in Manchester at the first available opportunity.
"Once he is back, I will sit down with him and explain my feelings and decisions will be made after that.
"He has rung me and he understands that we need to address this - and we will. Then we will move on.
"He obviously felt that there were certain things that he needed to address back home and so, wrongly, he made that decision to go back to Brazil.
"But he will be back at the weekend, then we will make sure that he knows my feelings and I am sure we will get a more detailed explanation from Robbie."
"He was on a plane back to Brazil when the Kaka deal was dead and buried.
"People trying to link the two are trying to cause a little bit of mischief."