West Bromwich Albion striker Luke Moore has been told he can still have a future at the Hawthorns.
Moore has just joined Derby County on-loan after being left out of the Baggies' Premier League squad list.
"The market opens again in January," said Di Matteo of Moore. "I've never shut the door on anybody.
"Scouts come to watch players on a weekly basis. January will come very quickly. You can change the squad then and this is a chance for him to play week in, week out, score goals and show his ability.
"We get requests from clubs asking which players are available on loan.
"Luke was one of those who was available."