Shevchenko, 31, salvaged a face-saving draw with a Champions League equaliser against Norwegian minnows Rosenborg on Tuesday night - having managed only 14 goals in 51 games in his first season.
And ex-England striker Shearer said: "I can understand it. He's come to a different country, a different culture but there's no way I would write him off.
"He's world-class and it would be very dangerous to do that.
"He scored, which will give him confidence. It's too early to write off a class player like him."