Simon Cowell has bronchitis

Simon Cowell has been sidelined by a bout of bronchitis.

The music mogul has pulled out of filming auditions for America's The X Factor in Kansas on Friday and Saturday so he can rest at home in Los Angeles.

Cowell has enlisted Irish music manager Louis Walsh to fill in for him on the judging panel alongside Britney Spears, L.A. Reid, and Demi Lovato.

Walsh, who managed Irish boybands Westlife and Boyzone, worked with Cowell for seven years on the judging panel of The X Factor.