Chelsea defender Gary Cahill has said that his team's effort will need to be "immense" if they are to secure a result from their Champions League first leg with Barcelona.
The two sides clash in the last 16 of the competition at Stamford Bridge on Tuesday, before the return leg takes place in Spain on March 14.
Cahill, who was a member of the Blues team that defeated Barcelona in 2012, has vowed to use the experience gained six years ago to produce a similar performance this time round.
"To keep Barcelona out, you have to be at your very best," the 32-year-old said. "When we beat them in 2012, the concentration at the back had to be at the absolute maximum. In terms of getting the ball and attacking, it was limited because they had long spells of possession.
"I was exhausted after we won the first game [1-0], mentally and physically. If you switched off for one minute, you knew they would score. Everyone will have to be at that level again, everyone will have to be so switched on.
"One lapse of concentration or focus, Barcelona will make you pay. It is still up to us to play, to create when we do have the ball. The effort it's going to take will be immense. Hopefully, this will be a contest to remember for the right reasons. If you can't get excited about this game, you shouldn't be playing."
Chelsea play Manchester City, Manchester United and Crystal Palace before travelling to Barcelona for the second leg.
