Campbell is being linked with Hull City.
"I like Fraizer both as a player and a boy. If anything was possible, we'd certainly look at it," said Tigers boss Steve Bruce.
However, O'Neill insists he is in no rush to sell Campbell after seeing his score in last weekend's defeat to Manchester United.
"Fraizer did really fine for us against United," said O'Neill. We will need him around here between now and New Year for a start.
"I would say we want to try to strengthen the squad if at all possible rather than let players go."