Rivaldo should never have left Barcelona, after that it's gone only one way with the former worldclass player. But maybe would a move to Bolton be a good thing, Big Sam seems to have a good relationships with his primadonnas. I'm sure money is the major factor here, Rivaldo hasn't looked for much else the last few years... but a move to the Premiership is probably also quite tempting, most players wants to try it before they hang up their boots - and the biggest clubs aren't interested in him anymore.
My thoughts; this could really go two ways - like Jardel (gone to Ancona with Ciccio and DINOsaur) or like Djorkaeff/Jay-Jay.
The latter will probably be on his way in the summer then, 'cause they surely can't afford having both.