I do not believe that any of them are intentionally dogging it. I believe that Hanley could put in more work on his defense, but I don't think it's a conscious effort on his part to say that he's not going to practice. From what I've read, he has willingly put in extra practice whenver one of the coaches has asked him to. I think he's too much of a flake to initiate it on his own.
With Pablo, I think he truly believed that his weight was not an issue, and before this year, it really hasn't been. Frankly, I'm not sure that it's the reason why he's been playing so poorly. If it is, then he needs to be put on a conditioning program. Regardless, he is giving his full effort on the field.
I don't see anyone else not giving their best effort, except for Ortiz in not running out grounders, but that is not anything new.