Devising a strategy to thwart Barcelona [ Images ] forward Lionel Messi [ Images ] is Chelsea [ Images ] coach Guus Hiddink's [ Images ] main concern ahead of his side's Champions League [ Images ] semi-final first leg at the Nou Camp on Tuesday.
The Argentina international is the top scorer in this season's competition with eight goals and Chelsea's task of preventing him from adding to his tally has been complicated by the suspension of left back Ashley Cole [ Images ].
Hiddink tried Portuguese defender Jose Bosingwa [ Images ], who normally plays on the right, in Cole's spot in Saturday's 1-0 Premier League win over West Ham but said he was still weighing up his options.
"I am not like that, I like to put the full energy and the confidence to (the player) who is substituting him in that position," the Dutchman added.
"Whoever is playing against Messi will have a tremendous job to do because he is the most productive player in the world and one of the players you like to watch, except when you play him."
Barca are the only non-English club left in the last four of Europe's top club competition for the second year in a row.
With the exception of long-term injury absentee Gabriel Milito [ Images ], coach Pep Guardiola has a full squad to choose from following the Primera Liga leaders' 2-2 draw at fourth-placed Valencia on Saturday.
"We have to rest and recover well because we are about to begin the most important week of the year," the former Barca and Spain midfielder said.
"I did not see any tiredness in the players," he added. "We are like a machine."
Midfielder Seydou Keita [ Images ] said the Barca players were well acquainted with their opponents and singled out Chelsea's physical presence as their main strength.
"The coach is doing some great work in preparing us for the match," the Mali international said at a news conference.
"He makes us watch a lot of the other team's games and we analyse their weak points and the dangers we could face."