Capello tried playing Rooney as a frontman behind Jermain Defoe - but the United star flopped, constantly running out of position.
Redknapp now believes Capello needs to push Roo into a wide right role - replacing Becks - in a bid to get the best out of him.
Redknapp said: "Wayne would do damage on the right. Becks is a good character to have around and is still a good player.
"But this is a position where Rooney could really do us proud in the World Cup qualifiers."