i don't think this is strictly a probability question as the behavioural tendency of the player comes into what he hangs on to try to catch in his last round or two
on the other hand, if he has been forced all in because he can't receive another hand, then you could use one of the
poker programmes to work out what you need to have to lose to a random hand more than 33% of the time
again, whether you could call in odds terms is different to what you should call in strategic terms
i think you should consider asking your question in one of the Tournaments forums