Rooney started his first Premier League match with new strike partner Robin van Persie as Manchester United beat Newcastle United 3-0 at St. James' Park on Sunday.
Shearer told The Sun that Rooney showed signs of genuine quality in the Newcastle match.
He said: "Looking fit again and firing on all cylinders, Rooney was everywhere at St James's Park.
"Helping out his defence, available for a ball from the back, on a wing to cross the ball and in behind Van Persie directly through the middle.
"When he is in this mood, he still ranks for me among the best in Europe. His touch, passing and energy made Manchester United tick.
"Perhaps that axeing for the game against Fulham and his time out injured have helped to refocus him."
The 26-year-old is yet to score for United this season, after spending nearly a month out injured with a deep cut on his thigh.