Stuart Broad has admitted England have been targeting the out-of-form Australia captain Michael Clarke during the Ashes.

“We obviously do a lot of research on him because he averages something like 52 in over 110 Tests which is remarkable, the career he’s had,” the England fast bowler said. “We talk a lot about him and we’re proud of the way we’ve bowled at him so far.

“We’ve made it hard for Michael. We know how dangerous he is. He is such a key player for them and it’s been going well so far.”

Clarke has endured a tough 12 months with the bat, with back and hamstring injuries restricting him to eight matches and 15 innings.

From those, Clarke has scored 365 runs at an average of 28.07 and has managed just one century.

Clarke goes into the Trent Bridge Test with his future under threat and Broad said England are keen to build on last week’s emphatic victory at Edgbaston. “It’s about resetting our minds again this week, it’s going to be a slightly different attack with [Jimmy Anderson] missing out, but it’s about making sure we are right on the money,” he said.

“Cooky [Alastair Cook] is very clear that it’s all about us this week. We had a great week at Cardiff. It’s about making sure our game plan is dead right and not to worry too much about what the Aussies are doing.

“We know they are a dangerous team. None of the Tests have been very close, have they? Not like 2005, where each game went to the wire. It’s been a fascinating series.”

Australia’s fast bowler Mitchell Johnson is confident his side can level up the series at Trent Bridge.

England would regain the Ashes with victory in the fourth Test, but Johnson said: “We’ve just got to focus on what we’ve been doing when we’ve been playing well. We’ve been training really well and that’s a positive for us. When we’re bubbly like that and doing our thing out there and focusing on what we need to do we generally come out and play our best cricket.

“It’s like a grand final for us, we really need to win this game and then focus after that.”