The Spice Girls star, temporarily replacing Kelly Rowland on the panel, is appearing at the Liverpool auditions alongside Barlow, Tulisa Contostavlos and Louis Walsh.
Barlow told The Mirror: "I know Geri Halliwell and I think she will make a good guest judge and we could be seeing more of her on the show."
The Take That singer revealed that he feels more "relaxed" about his second series on the ITV talent show, having admitted last year that he was "not enjoying" the live shows.
The 41-year-old added: "Looking back on last year the live shows were so intense.
"You have just sort of got to go, 'F**k it' and let your shoulders down and go, 'Hang on a minute, I am in control here, I can take as long as I like'.
"You have to have that attitude. I have got a year under my belt and I feel relaxed and excited."
Picture gallery - X Factor's first auditions in Liverpool today:
Copyright: Rex Features McPix Ltd