Shevchenko told the Daily Star: "Torres hasn't become a bad player overnight - that just doesn't happen.
"You don't go from being world class one minute to no good the next. When a club has paid a lot of money for you, that obviously brings it's own pressures, but you just have to go out and do your best on the pitch, and I know Torres does that.
"Great strikers don't suddenly forget how to score goals.
"The reason Chelsea paid such big money for him is that he is one of the best strikers in the world, and that doesn't change.
"I was watching him play on Tuesday when he didn't score but made two important assists for the goals. That shows he's putting it in."