"The fans have certainly taken to him, and I like him," Williamson told the clubs official website.
"I think he's a fantastic talent. He's still got a lot to learn and he may learn it with us. I do substitute him from time to time because he does run out of steam. He covers every blade of grass.
"That will come with experience. Once he starts learning the game, he will be a better player, and I hope it's with us.
"There was a transfer-fee figure in place that we could work towards if he enjoyed being here and we enjoyed working with him. I think both parties have shown we do like each other."