I think the Rasmus stuff might be convenient narrative -- do we really know he has "all the talent in the world"? I think for a lot of guys, failure or even streaks of success and failure are pretty much their full potential. Not everyone can succeed or sustain success, that's just not the way MLB or life works. I certainly wouldn't dedicate a lineup spot and $10 mil to enlist an attitude adjuster to try to achieve that ideal. And the examples often cited around Hunter -- Puckett to Hunter, Hunter to Span, Hunter to Trout -- seem pretty mild in this regard. I am sure the mentored player appreciated it, but none of those guys experienced the wild on-field performance trough/swings of a Hicks or a Rasmus. In this field, and at this level, that's not something a friendly mentor is really going to make a dent in. On the field, the overwhelming factors are your own talent and skill, with the possible wildcard of expert level coaching which I wouldn't expect from anyone let alone a fellow active player.