Houllier was pretty brutal with Xavier.
I think he was bought by Thompson when Houllier was off. When Houllier returned he didn't waste a lot of time in sending him out on loan and very publicly saying he wasn't welcome back.
Weird, that. Steven Wright had played a few games at RB and I for one thought he'd done OK, but GH binned him off for Xavier, only then to turn on him like that. Once you got into GH's bad books there was never, ever a way back.