As part of England's Euro 2022 winning squad, Walsh has experience of playing at some of the world's biggest stadiums including Wembley.
However, the 25-year-old thinks the Nou Camp is the best she atmosphere she has ever experienced.
"I'd never experienced a football match like that before, the passion was next level," she added.
However, Walsh - who became the world's most expensive female player when she joined Barca from Manchester City last summer - will not be backed by her football-mad father at the game.
