The former Premier League champions head to Spain with a 1-0 advantage and with Didier Drogba's fitness up in the air, Torres could be called on to lead the line for Roberto Di Matteo.
"On the counter-attack [Torres is] going to be very dangerous, always a threat on the shoulder of the last man," the Daily Star quotes Mata as saying.
"We're capable of scoring at the Nou Camp. We can hurt them on the counter-attack. The Nou Camp is a big pitch, and they're going to try and open up the spaces. But we're always dangerous on the counter in those situations, especially the more open it is."
The former Liverpool frontman has netted just two goals in his last 35 appeareances for Chelsea.