Strauss said from a player's point of view it is "up there with the Ashes".
The England captain added: "It's the highlight of the summer. It is hard, competitive cricket between two good sides going toe-to-toe."
Strauss confirmed Bopara would make his 13th Test appearance and his first in almost a year.
"He's played really well in the one-dayers and looks very comfortable with himself and his game. He also has the ability to bowl some handy overs for us," said Strauss.
"He's a good guy to have at six for us and I'm sure he'll be really glad to grab this opportunity with both hands and cement that spot."
Analysis: England v South Africa
Alec StewartBBC Test Match Special
“It's a really close call, because it's the most evenly matched contest that we've seen for a long time but I'm backing England to win by one and retain their status as the world's number one Test nation”
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