The Real Madrid left back has heaped praise on the winger after his outing Saturday but says he still has work to do to be mentioned in the same breath as the Portuguese star.
Los Blancos stormed to victory on Saturday, with Bale opening the scoring with a header 33 minutes in before Karim Benzema made it 2-0 three minutes later.
The world's most expensive player added two more goals in the second half with his right and left foot to complete the perfect hat trick and leave onlookers comparing him with teammate Ronaldo, who missed out through injury.
Marcelo told reporters: "You cannot compare Bale and Ronaldo. Cristiano is above the rest of the players and everyone on the team knows that. Bale is a great player, though, and he is on the right track."
Madrid's victory has closed the gap between third-place Madrid and top two Barcelona and Atletico Madrid to three points, with the Blaugrana set to face Athletic Bilbao on Sunday. But despite the comfortable nature of the victory, Marcelo targeted further improvements to performance after the game.
"Every game is difficult and Valladolid did not allow us to play at first, but then we got well set defensively and offensively," the 25-year-old added. "Our first goal is always to win the game - whether we play well or badly. But we also have to put a show on for the fans and in recent games I think we have improved a lot. We kept a clean sheet as well and that is important for us."