A jaded-looking Chelsea need to find an extra gear if their runaway season is not to hit the wall over the next week.
The Premier League leaders had the best of the first half against Liverpool in their eagerly anticipated all-English Champions League semi-final first leg at Stamford Bridge on Wednesday but faded in the second to finish 0-0.
They have raced 11 points clear in the domestic league, qualified for the knockout stages of the Champions League with two games to spare and beat Spanish league leaders Barcelona and German leaders Bayern Munich to reach the last four.
A string of injuries and the sheer number of matches for club and country that most of the team have played, are beginning to tell, however.
Portuguese manager Jose Mourinho put an upbeat spin on the game, saying he was delighted with the result and confident of a place in the final.
"We have got goals in Liverpool and they have to play a different way and it is very dangerous for them," he said.
"They play at home and 99.9 per cent of Liverpool fans will be thinking they are in the final but they aren't and it will be difficult for them."
Liverpool need to win. Because of the away goals rule, Chelsea need a score draw to reach the final in Istanbul next month.
Before the return at Anfield next Tuesday, Chelsea may also be distracted by the need to grab the final two points that will guarantee them the Premier League title.
To do that they must travel north to Bolton, not far from Liverpool, tomorrow to face a tough and uncompromising side battling for a place in Europe next season.
With their two first-choice full backs out long-term, scratch left back William Gallas strapped up and playing through a back injury, winger Damien Duff suffering a hamstring strain and the magical Arjen Robben far from match fit on his return from a foot injury, Chelsea cannot afford to take risks.
Mourinho always says it is a waste of time bemoaning injuries. He said before this tie, however, that his side had been particularly badly hit.
"When we get an injury it always seems to be a serious one," he said.
Both Chelsea and Liverpool declared themselves satisfied with Wednesday's result, Mourinho pointing out that when he won the Champions League with Porto last season his side drew 0-0 at home in the semi-final and went on to win the second leg at Deportivo La Coruna.
Liverpool manager Rafael Benitez said: "We know we can only win at Anfield."
Anfield certainly has the power to intimidate visitors. Chelsea, who have beaten Liverpool three times this season, scraped a lucky league win there in December.
Chelsea midfielder Frank Lampard, who has played 53 club games so far this season as well as England matches, missed an open goal in the first half on Wednesday. He said his side would be looking forward to the Anfield challenge.
"It's a massive game. We were fortunate to win 1-0 there earlier in the season and we'll have to be on top of the game to get the right result."