Which begs the question: what went wrong with those two guys?
A quick search through the archives turns up the Carlos Quentin/Joel Guzman Smackdown where Guzman was noted to have Miguel Cabrera-type ability "if he can gain sufficient command of the strike zone" but a comment in 2006 compared him to (ack) Richie Sexson (admittedly, in the Richie Sexson prospect retro). I'm assuming he just hasn't gotten that command, but has he been THAT bad that he couldn't get a chance to prove himself at the major-league level? Coming into the year, he'd only had 56 AB's between LA and Tampa Bay and put together a sparkling .232/.306/.321 line, but he's also only 23. Is there any hope for him (not like they're moving him back to SS, ha ha)?
Which brings us to Daniel Ryan Johnson. He was ready to come up in 2005, did so, and this here review points out that his power and patience were expected to be useful (he did kinda go .275/.355/.451 in 109 games for the A's). Aaaaaaaaand so far, in 1000+ AB's, he's gone .249/.344/.419. Matter of fact, tonight's pinch-hit appearance was his first at-bat since April 2. He was hurt in 2006, stunk out loud in 2007... just a question of old player skills?