Rooney appeared wound up when he appeared as a second-half substitute during England's 3-0 win over Platinum Stars in their final warm-up game for the finals.
The Manchester United striker was guilty of a late challenge on Kagiso Senamela and was then booked for dissent.
He appeared in a similar frame of mind in the international with Japan in Graz nine days ago.
But Defoe has leapt to the defence of the 24-year-old, who was sent off in the 2006 quarter-final against Portugal.
The Tottenham striker said: "If under control, I think Wayne's temper is a good thing.
"When you've got that fire in your belly as a player (it can be good). If you take that away from Wayne, then he won't be the same player."