Guillermo Antonio Quiroz [gee-YARE-mo kee-ROZE] (born November 29, 1981 in Maracaibo, Venezuela) is a Major League Baseball catcher who is currently in the San Diego Padres organization.
Quiroz was signed by the Toronto Blue Jays as a non-drafted free agent in 1998, before his 17th birthday, with a lucrative $1.5 million signing bonus. He progressed through Toronto's system as the team's number-one catching prospect. In addition, Baseball America rated him as the Blue Jays' third best prospect in their 2004 pre-season rankings, and the 35th best prospect in all of baseball.
Defensively, Quiroz has good skills. In 2003 he threw out 45% of base stealers, and was the starting catcher for the World Team in the 2003 All-Star Futures Game.
Despite his low average in the minors, Quiroz is a patient hitter who receives a significant number of walks and can hit with decent power. He missed the end of the 2003 season with a collapsed lung, and the broken hand he suffered in May 2004, hurt his chances of taking over as the Blue Jays' starting catcher in 2005.
In 2006, the Blue Jays signed catcher Jason Phillips initially as the backup to Gregg Zaun.