Quintanilla, who has spent parts of each of the past five seasons in the Majors with Colorado, tested positive for Methylhexaneamine -- a performance-enhancing substance -- in violation of the Minor League Drug Prevention and Treatment Program.
Quintanilla sprained his left knee in Spring Training and was sidelined for two months before starting his season with Triple-A Colorado Springs. He hit .252 with a homer and 15 RBIs in 34 games with the Sky Sox before undergoing arthroscopic surgery Aug. 2 to remove loose bodies from his right elbow. He was transferred to Class A Short-Season Tri-City's roster and was expected to miss four to six weeks.
Wednesday's suspension from the Commissioner's Office will ensure that much, at least.
In a statement, the Rockies said, "We were very disappointed to learn that Omar Quintanilla has been suspended after testing positive for a performance-enhancing substance.
"We have routinely educated our players about the dangers of performance-enhancing substances and strongly encourage all players to avoid their use. We strongly believe that baseball and all other sports must continue to directly address the issue of performance-enhancing substances. There is no place in baseball for such substances, and we have and will continue to do what we can to eliminate them from our game."
Quintanilla is the 74th Minor Leaguer to be suspended in 2010 in violation of the Minor League Drug Prevention and Treatment Program. He's also the latest player to test positive for Methylhexaneamine, a stimulant initially intended to be used as a nasal decongestant.
Former Ohio State captain Zack Hurley, Oakland's 29th-round pick in June's Draft, has strongly vowed to fight his 50-game ban after testing positive for Methylhexaneamine last week. Hurley said he would "go to war" to fight the suspension and claimed he only took an over-the-counter supplement he knew as "Jack," which he said did not contain any banned substances.
Quintanilla received about $1 million when he signed with Oakland after being selected in the first round out of the University of Texas. He was shipped to Colorado with Eric Byrnes and cash considerations in exchange for Joe Kennedy and Jay Witasick on July 13, 2005 and has seen time with the Rockies in each season since.
He spent all of 2009 in the Majors with Colorado, appearing in a limited role in 58 games.