"We were very disappointed to learn that Mike Jacobs had been suspended after testing positive for a performance-enhancing substance," the Rockies said in a statement Thursday.
"The Colorado Rockies have long been committed to eliminating the use of performance-enhancing substances from the game of baseball. We have fully supported the adoption and implementation of the Major League Baseball and the Major League Baseball Players Association joint drug prevention and treatment program."
Jacobs, who has played 556 games in the big leagues with the Mets, Marlins and Royals, was in his first year in the Rockies' organization. In 117 games at Colorado Springs, Jacobs batted .298 with 23 home runs and 97 RBI.
Jacobs apologized in a statement and said he used HGH to try to overcome injuries.
"A few weeks ago, in an attempt to overcome knee and back problems, I made the terrible decision to take HGH," Jacobs said in the statement. "I immediately stopped a couple of days later after being tested. Taking it was one of the worst decisions I could have ever made, one for which I take full responsibility.
"I apologize to my family, friends, the Colorado Rockies organization, Major League Baseball and to the fans. Now, as required by the minor league drug program, I will serve a 50-game suspension. After my suspension is completed, I hope to have the opportunity to continue my career in the game that I love so much."
The Rockies signed Jacobs as a minor league free agent in December. At the time, they had not resigned first baseman Jason Giambi, who like Jacobs is a left-handed first baseman, as is Todd Helton, the Rockies' starter at that position.
Ty Wigginton gives the Rockies a right-handed hitting alternative at first base.
So while Jacobs was in big league spring training with the Rockies, he gave them organizational depth at first base with little chance of getting to the big leagues, barring a series of injuries.
The New York Times first reported Jacobs' suspension.