The former Man City boss said Riviere seemed half-hearted and not the sort of player he wanted in his squad.
Mark Hughes: "We had conversations with people close to him.
"There was an indication he may be available this summer so we pursued it to a certain extent.
"We were able to offer decent money but there has to be a feeling that the enthusiasm we have for a certain player is reciprocated.
"We didn't get that from the player or his advisers."