It has been the week of the basket case at Stamford Bridge but, amid the covert operations in the laundry and the baffling press conferences, it is clear that there is method in José Mourinho’s madness. “When you build a house you do not start with the roof,” he said after criticism of Chelsea’s style first surfaced. Now that defensive strength faces one final test before work on the penthouse begins in Athens.

Liverpool must find a way to breach a back four protected on either side by those twin enforcers Petr Cech and Claude Makelele. It is a task that Steven Gerrard, whose volley in the first leg of Wednesday’s Champions League semi-final was the closest Liverpool came to a goal, knows is a Herculean labour. “We dominated possession in the second half but without creating clear-cut opportunities,” he said. “Then the ’keeper pulled off a top save. I don’t think any other keeper in Europe could have got to that.”

Gerrard is the emotional epicentre of the side, but his hope that Chelsea will cave into the raucous Anfield atmosphere smacked of straw-grasping. If Liverpool do overturn the 1-0 deficit it will not be down to the crowd so much as their their ability to rattle a defence that has conceded only 12 away goals in 18 Barclays Premiership matches.

Central to that meanness has been the resurgence of Ricardo Carvalho. “John Terry is one of the best in the world, but I’ve massive words of praise for Ricky,” Frank Lampard said. “He doesn’t go looking for the limelight and, along with Michael Essien, is one of the unsung heroes.”

Carvalho’s relationship with Mourinho has not always been a mutual love-in. When he was dropped in 2005 he responded by saying it was “incomprehensible” that he was third choice, adding that he had not had “an easy relationship with Mourinho” at FC Porto either. Now Carvalho is fundamental to Chelsea’s hopes of erasing the memory of the semi-final return leg of 2005, when Liverpool scored their “ghost” goal after only three minutes and Anfield pulsed with adrenalin.

“People talk too much about intimidating atmospheres,” Lampard said. “What’s the problem? Every player should be up for this. We weren’t intimidated then — it was a great atmosphere, but because they scored one goal and won 1-0 people said it was intimidating. We have too many characters — we did then and we have now.”

However, Liverpool can take some solace from Chelsea’s teak-tough backline having proved less effective in Europe where they have conceded in every away game this season. “Chelsea will show us a lot of respect,” Gerrard said. “They know the tie’s not over. We’re confident we can hurt them a lot more with our crowd behind us.”

Mourinho will be flushed with even more confidence than usual, however, as Joe Cole’s strike means he can give full rein to his inveterate conservatism and resist the need to press for a goal. With the defensive quartet of Cech, Terry, Carvalho and Claude Makelele in such assured form, Chelsea believe they can keep hold of what they have. Mourinho might even start to think about booking that roofer.

Hard to beat

1 Number of goals scored against Chelsea in past ten league games

8 Number of consecutive cup games – Champions League, FA Cup and Carling Cup – in which José Mourinho’s team have failed to keep a clean sheet before shutting out Liverpool on Wednesday

54 Attempts on Petr Cech’s goal in past four games – 13.5 per game on average

75 Efforts on the Chelsea goal in the previous ten games, an average of 7.5 per game. These figures suggest that Chelsea’s defence has become a little less efficient as the season draws to a close