Lancaster eyeing second spot
Stuart Lancaster has set England the target of replacing South Africa in second place in the world rankings by the end of the season.
England are third in the standings and are hoping to register their ninth victory in 10 matches when they play Argentina in Saturday's QBE International at Twickenham.
New Zealand have a near-unassailable lead at the summit of the International Rugby Board's rating system, but Lancaster believes South Africa can be caught.
"Our win against Australia on Saturday has widened the gap between us and fourth place," he said.
"If we can keep our winning record up we'll close the gap. South Africa have to keep winning too. That's why Argentina is a game we must win.
"I mentioned it as a goal right at the outset and we're actually close to achieving it ahead of schedule.
"The reason I use the rankings as a goal is that I like to set performance goals and outcome goals.
"Anything you can use to give the players an extra sense of motivation and reason why the next game is important, you use it.
"It's a good measure of our improvement and we want to make sure it's a positive things and we can keep building towards it."