Capello: Brazil test key to England progress
"It will be really important for me because you are playing against one of the best teams in the world," the Italian told a news conference on Friday.
"This is very important for me to understand the different style and what we will have to do in the future when probably we will have to play in South Africa against a South American team."
England are without several injured regulars in Doha but Capello said the game would represent an opportunity for fringe players.
"Every game is very important for me," he said. "We are missing a lot of players who played in World Cup qualification but this is a big chance for some (other) players to promote themselves."
Midfielder Frank Lampard was the latest established player to pull out after tearing a thigh muscle in training in the Middle East.
Steven Gerrard, Rio Ferdinand, Ashley Cole, Aaron Lennon and David James are other absentees.
Captain John Terry was also a concern after twisting his ankle while running but Capello was confident he would be fit.
"I think tomorrow he will be ok," said the coach.