American trialist Devann Yao had had a successful trial with Championship Ipswich. The 19-year-old striker has already spent most of his footballing career in Europe.
He has now trained with Ipswich and impressed during a behind-closed-doors game with Celtic where he scored one and set the other up in a 2-2 draw.
"Devann did well. He had lots of energy and can be pleased with his performance," boss Roy Keane said.
"He had a hand in both goals, and hopefully we can do something. We will offer him a contract."