The Blues travel to Camp Nou on Tuesday to face the competition favourites and Hiddink has vowed to attack Pep Guardiola's men as he goes in search of an away goal.
Hiddink insists Chelsea will not sit back and allow Barcelona to dictate play, as he believes they need to be courageous if they are to reach next month's final in Rome.
"This team has to go for it," said Hiddink.
Courage"Chelsea are not a team who can sit back and wait for one or two counter-attacks. We must play courageously.
"That's why it's important, in two legs within a week, to take the initiative. It's important to score in Barcelona given it's a two-legged tie, so we can have a big chance at home as well.
"We have to take the advantage and the courage to play. It would be wonderful if the team could get to the final for the second year in a row."
Chelsea will come up against a galaxy of stars in the Barcelona side, but Hiddink believes Didier Drogba could be his trump card against the Spaniards.
"He's very important. He is a very charismatic player, fighting for the team," added Hiddink.
Efficient"He's also very efficient with his productivity and he knows what to do. He knows, also, what not to do. That's very important."
When asked to explain what he should not do, Hiddink referred to Drogba's history of play-acting.
"He knows not to over-act. He knows when he has sides on edge, he's always dangerous," added Hiddink.
"We haven't spoken to him about over-acting particularly today but he knows how he has to play and he knows the importance, of course.
"He's brave and whoever he plays against will have to be brave to play him.
"It'll be very interesting. When you play in a semi-final it can go either way but there will be big clashes between big players."