The 23-year-old, who left his home country for England in 2008, was recently overlooked by coach Luiz Felipe Scolari for the Confederations Cup.
"People think I don't want to play for Brazil because I left at such a young age," the 23-year-old told PA.
"That is not true at all. My brother and I left because life for any young Brazilian player is full of uncertainty. It is the same in England but we knew Manchester United represented a big chance for us.
"The people back home thought we didn't care. We do care. I would love the chance to play for my country again."
Rafael has won two caps for Brazil since making his debut in 2012.