The 17 year old defender has been offered a contract for next season after missing most of this season through injury.
"Grandison has missed a lot of football though injury because he had a problem with his hips," said Chris Coleman to the CT. "He's only 17 and is still growing. He is a good prospect and I might throw him in.
"I don't think I will start him but I may give him half-an-hour to see how he does."
Birmingham born Jermaine's brother Joel plays for City's U18's.