A win against PSV on Wednesday will guarantee Barca top spot in in Group B and a last-16 clash against a runner-up from one of the other groups.
Vidal highlighted the prospect of winning the Champions League as one of the main motivations behind his move from Bayern Munich to Camp Nou ahead of the 2018-19 season.
But put to him that he might put his mohawk on the line and shave it off if Barca go all the way in Europe, Vidal was not prepared to entertain the idea.
"No way!" he said.
"I do hope that Barca wins the Champions League but I'm not going to change my style because of that.
"I hope to keep this [hairstyle] as long as I'm playing football."
"I'm happier with more minutes and I'm playing more," he added.
"I have more confidence, I'm happy and I hope to continue helping the team when they need me.
"Barca have special players and I want to feel important. I want to help the team reach its objectives.
"I'm in good form but I hope to keep improving. I'm yet to reach my best but I feel good and I feel confident."