Hobart, Jan 16 (IANS): Former England captain Sir Alastair Cook said on Sunday that the thrashing in Hobart handed to Joe Root's side 'has to be our rock bottom'. Cook's comments come after England had a dismal collapse yet again to end the Ashes with a 146-run loss. England crumbled from 68/0 to 124 all out in just an hour and a half on day three of the pink-ball affair.

"That was very tough viewing, that has to be our rock bottom, there cannot be a worse place than getting bowled out in an hour and a half. You competed in this game with the ball, but I actually can't believe an hour-and-a-half to lose 10 wickets, that's the biggest shock as a batter and a professional who plays cricket," Cook told BT Sport.

"You don't win games of cricket (batting in that manner). The fact we've lost 10 wickets in an hour and a half... yes the conditions are tough, and some good bowling, but there was no resilience there," added Cook, who was the player of the series when England won the Ashes in Australia in 2010/11.

Cook felt the collapse was inevitable once Rory Burns was dismissed in the 17th over. "You get bowled out in a session once or twice in a career and this side, after a couple of wickets, we said 'something is on here' and you see a batting line-up devoid of all confidence, once they lose one or two, no one steps up and stop the slide."

"I said at the beginning of the game it was going to be a really hard week for them mentally because they're about to lose, go home, the thoughts about that, and as soon as they get put under pressure you see how much resolve there is. They showed a lot at Sydney but probably used it all there."

Talking about his review of the series, Cook remarked that there is a huge gulf between Australia and England. "It has probably been the least competitive series between the sides. I have been involved in two 5-0 defeats so people may accuse me of being biased, but I just feel there is a very big gap between the sides. We need to look at everything, start rebuilding this Test team."

"No stone can be left unturned as it has to be better. That last hour and a half showed where we are. You can talk all you want about the battle in the dressing room, but until some people grab it by the scruff of the neck, I can't see this changing."

England's next Test assignment after the 4-0 Ashes thrashing will be a trip to West Indies in March. Cook believes that he will be surprised if the same shape of the Test side will be retained for the Caribbean tour. "I will be very surprised if England go to the West Indies in March with exactly the same structure in place. I'm not saying Joe Root won't be captain but I can't see how there won't be some changes."

"We have had the same coaches in place for 18 months now and I've not seen any improvement, really, in anything. What has been going on behind the scenes? You have to ask questions of Graham Thorpe, the batting coach, and the others. If you have the same leadership group in the West Indies and England lose, their positions will be untenable and there has to be changed."