Trailing 3-0 in the series and with the Ashes already gone, Cook has lost veteran spinner Graeme Swann to a surprise early retirement since the previous test in Perth.
Pace bowler Jimmy Anderson appears out of form, fellow quick Stuart Broad has a right foot injury and wicketkeeper/batsman Matt Prior’s place in the team is in doubt. Spinner Monty Panesar is expected to return to the side for Swann.
“Losing the Ashes and with Swannie going as well, it has been a different week,” Cook said.
“When you lose games of cricket, naturally your confidence does slip. We’re desperate to turn it around and you don’t often get the chance to play a Boxing Day test match at the MCG.”
About 90,000 are expected at the Melbourne Cricket Ground on Thursday for the first day of the test. While few foresaw Swann’s sudden retirement, Cook was not surprised as he felt the spinner had nothing left to give.
“It’s a brave decision. It was quite an emotional chat,” said Cook.
Cook said he was encouraged by Broad’s bowling in the nets. Broad was hit in the right foot by a Mitchell Johnson yorker in the third test but scans showed no fracture. “The signs are good,” Cook said Wednesday.
Australia captain Michael Clarke said his team was “extremely shocked” by Swann’s decision to end his international and first-class career.
“He’s been a wonderful cricketer for a long time for England and deserves a lot of credit for what he’s achieved,” Clarke said after Wednesday’s training session. “He’s the type of character you enjoy having around your group, especially when you’re away from home and family and friends.”
Clarke said Australia won’t let up in the remaining two tests, using the matches as a build-up to its tour of South Africa in February. He also said he wouldn’t be caught up in the euphoria of the Ashes victory because the side has won just four of 13 tests in 2013, including four losses in India.
“I’ve seen both sides of this game,” Clarke said. “I know how quickly you can be praised by the media and I also know how quickly you can be criticised.
“I’m not silly enough at 32 years of age to look past tomorrow, because I know a couple of ducks and my job’s on the line or a couple of losses and I’m under the same pressure.”
Clarke is aiming to join Warwick Armstrong (1920-21) and Ricky Ponting (2006-07) as captains who have led Australia to a 5-0 series sweep over England. Clarke said Australia would take in the same 12 as Perth, meaning all-rounder James Faulkner, who has a broken hand, will likely be 12th man.
“At this stage everyone seems fully fit. I haven’t looked at the wicket yet,” Clarke said. “It’s more about assessing the conditions tomorrow morning before we announce our 11.’’
England will also wait until just before the toss on Thursday to name its team, with one change expected to be Jonny Bairstow in for Prior as wicketkeeper.