Campbell has no first team coaching experience, but insists he could take the job.
He told ESPN: "I think there is a lot of soul-searching [for the U.S. to do]. I think the main thing you've got to look at [with] America is where do they go now? They've invested a lot of money, and I think sometimes you've got to look in different areas. You can't always look in the same places.
"Yes, they want to keep it local, and they want to keep as much in USA with the players and the staff, but sometimes you've got to open up. I think there's guys around the world who could contribute.
"Maybe not [people] on their hit list, maybe not on the paper list, maybe not on the agent's list, but guys who probably could help them in different ways on the field: attack-wise, defence-wise.
"Who knows? If they came to me, maybe I could help them out. Who knows? But I think they have got to start looking in different directions."