Celtic are poised to launch an audacious bid to sign Manchester City midfielder Joey Barton with Stilian Petrov going in the opposite direction. Both Barton and Petrov want out of their respective clubs and City manager Stuart Pearce is a known admirer of the Bulgarian playmaker. Barton was in fantastic form last season but rocked the blue half of Manchester by submitting a transfer request, although it remains to be seen whether a move to Glasgow would interest the loveable Liverpudlian.