England skipper Alastair Cook believes aggression has helped his side curb the influence of Mitchell Johnson.

Johnson claimed a staggering 37 wickets in the 2013-14 Ashes to be the driving force behind Australia’s 5-0 win.

The left-armer has managed only 11 wickets in the first four matches of this five-Test Ashes series.

The express paceman had his moments in the second and third Tests, but naturally found it hard to defend low totals at Edgbaston and Trent Bridge.

Cook conceded local conditions helped his team negotiate their nemesis, but felt their intent had also played a part.

“We’ve played him a bit better,” Cook said.

“On the whole, we think we’ve played him very well, played all their bowlers pretty well – and we’ve scored at a good rate.

“We might have lost wickets as the game has moved forward but our scoring rate has been impressive.

“They haven’t managed to tie us down as well as we’ve managed to do with them.”

Joe Root has led the charge, scoring two tons to be the leading run-scorer and Stuart Broad’s main rival for man-of-the-series honours.

Root was already viewed as England’s golden boy and Cook’s obvious successor as captain.

But the 24-year-old has taken his game to another level over the past two months to claim top spot on the ICC’s Test batting rankings.

“He’s improved leaps and bounds. I’ve never seen a player improve like that,” Cook said.

“He kind of bats the same way in Test matches as he does in one-dayers.

“To not have to change your game much to play different formats can only be a good thing.

“That’s a huge credit to Joe. It’s a pleasure to watch him.”

Cook praised Michael Clarke, as he did after the fourth Test, but wouldn’t be drawn on whether England had any specific plans to farewell the outgoing Australian skipper.

“Hopefully, not half-volleys,” he laughed.

“Michael has been a wonderful cricketer for Australia and, hopefully, he’ll be remembered for all the right reasons.

“Australia will miss a mighty fine batsman and a very good captain.”