Hughes knows Onuoha well from his time at the City helm and, speaking last week, said he would give him time build up his fitness.
"The lack of playing time would be factored in," Hughes said. "We would be mindful of that.
"We have to understand he has not had a lot of game time but he is a player I know and as an individual as well.
"I am sure he will be very keen to make an impression very quickly."