They say that you have to hit the bottom before you can start to get back up. And that is where this Australia team are right now, rock bottom, after a run of six straight defeats to India and England. If these players have not heard the wake-up call by now, then they do not deserve to be in the Australia team. They have to turn this series around right now. If they don't, some of the blokes in this squad could find that their international careers end with the fifth Test at The Oval.

Plenty of English fans have been telling me this is payback for all those years when their side couldn't even get a sniff of a series victory in the Ashes. I remember in the 1990s and early 2000s it seemed like every time we played there were a hundred different explanations each time England lost. We're seeing something a little similar in Australia now. Everyone wants to find a reason. To me a lot of those reasons sound like excuses. I'd say it is all pretty simple really, the 11 men in the team need to play better.

I believe they can do it, too. Specifically Australia need to do two things. They have to improve their spin bowling; and the batsmen in the top six need to put a higher price on their wickets. The first of those is the easier to fix. Nathan Lyon, between his debut in 2011 and the start of this series, took as many wickets in Test cricket as any other Australian bowler, 76 at an average of 33. He should start the next Test.

I also expect Fawad Ahmed, who just took eight wickets in a match for Australia A in Zimbabwe, to come into the squad. I like Ashton Agar and admire his energy but on these dry pitches we need a spinner who can make more of an impact on a match than he is able to at this early stage in his career.

Agar's 98 at Trent Bridge masked the weakness of Australia's batting, which was so glaringly exposed at Lord's. There have been problems here for a little while. In the Australian summer the top order got away with underperforming because they had Mike Hussey at No6, and he and Michael Clarke combined to make an excellent safety net when things went wrong. With Hussey gone, the senior players in the side are going to have to take more responsibility for getting working totals on the board.

That starts with Shane Watson. I like Watson, too. He is great to watch because he has all the shots and scores at a real lick when he gets in, but he also has a sound defence. I'm getting a little tired of pointing all that out.

He has always promised a lot and now he has to deliver. I think he needs to score at least a couple of hundreds in what is left of this series, because he is one of those guys who is, potentially, at crunch time in his Test career. He may want to look to start playing straighter because I know, if I was bowling at him, I would be looking to set him for the lbw, just as James Anderson has been.

Some wonder if Watson is the right man to open. But right now who have Australia got who will do a better job? David Warner has not scored many runs for the A side since he left the country and, from what I have heard, has not been looking in much touch in the nets either. That sums up the situation. There aren't any standout candidates to come into the squad who would make a real difference to the batting. The guys who are in the team now are the ones who are going to have to do it for Australia.

One encouraging thing is that, apart from Watson, everyone in that top seven has made a fifty in this series. Phillip Hughes may have a deficiency against spin but he showed at Trent Bridge that he can still graft out an innings. Usman Khawaja may have looked a nervous wreck in the first innings at Lord's but second time out he showed how good he could be when he is feeling more relaxed.

They are a team under siege from their own media and the opposition. But they have to shut all that out and be honest with themselves and each other about what they have done and what needs to change. Because the truth is that this England team is not unbeatable. At Lord's they were 30 for three in both innings. Their two key batsmen, Kevin Pietersen and Alastair Cook, have barely made 160 runs between them in eight innings.

That has all been overshadowed by Australia's bad batting. There are weaknesses there for Australia's bowlers to exploit, but they cannot do it unless the batsmen start performing.