Guillermo Quiroz is an interesting player whose future appears to be filled with plenty of uncertainty. Once touted as Toronto's catcher of the future, he's now fighting for a chance to prove himself in the majors.
He signed with the Blue Jays as a 16 year old and went on to spend his age 17 season playing for Medecine Hat in the Pioneer League. Offensively, it took him several years to mature. However, much like Alexis Rios, he enjoyed his breakthrough season in 2003 while playing for New Haven (AA). He posted a line of .282/.372/.518, terrific numbers for a catcher by any measure. And in 2004, Baseball America named him the 35th best prospect in all of baseball, two spots ahead of the recently acquired Sergio Santos. Although Baseball America named him the 79th best prospect in baseball prior to the 2005 season, it was almost certainly based solely on his 2003 accomplishments. In 2004, Quiroz posted a line of .227/.309/.404 in AAA, and a line of .212/.263/.250 during his short stint with the Blue Jays. The silver lining is that he was only 22 years old, so his poor stats could be attributed to adjusting to a new league. He didn't adjust as the Blue Jays organization would've hoped, however. He struggled with a wrist injury for a significant part of the season, and failed to post an OPS above .800 in either of his three stints that season (A, AAA, MLB).
In a sense, Quiroz's career path is very similar to Alexis Rios'; he peaked in 2003, but has since been unable to prove that it was nothing but an aberration. Was something going on in New Haven that season to skew their stats? In order to see if their situation is the rule rather than the exception, let's contrast the 2003 stats of the five most (perhaps only) promising prospects on that team with their 2004 stats:
Unfortunately, I don't have access to OPS+, BABIP, etc. for the seasons in question, which would have been very helpful. But from the table posted above, it's evident that Quiroz and Rios are the only two of the five who regressed significantly during the following season. As a result, their change in environment is likely not the sole explanation for their sudden lack of production. Every facet of their games, from getting on base to power production, were but shells of their former selves.
As of now, Quiroz will need to have an impressive spring to beat out Jason Phillips in order to make the team. The potential signing of Bengie Molina only further complicates the issue. Unlike with Rios, the Blue Jays have shown no indication of giving Quiroz an extended opportunity to hold down the starter's job, nor should they. Other than his 2003 season, he has shown no indication that he's capable of being capable everyday player in the majors. Unfortunately, I wouldn't be surprised if he's no longer in the organization a year from now. Much like a former promising Blue Jays prospect, Kevin Cash, his time with the organization has been marred by unrealized expectations and unexpected realizations.