Buster Olney breaks down Houston's decision to part ways with first baseman Jon Singleton, who is currently serving a 100-game suspension. (1:31)

The Houston Astros have released former top prospect Jon Singleton, who currently is serving a 100-game suspension for a third positive drug test.

The team made the announcement Monday night.

Singleton, 26, a first baseman, played for Double-A Corpus Christi last season and hit .205 with 18 home runs and 62 RBIs. He tested positive for a drug of abuse and was suspended by Major League Baseball for 100 games in January.

Drafted in the eighth round by the Philadelphia Phillies in 2009 and acquired by the Astros in the Hunter Pence trade in July 2011, Singleton hasn't played in the majors since 2015, when he went 9-for-47 in 19 games. He played 95 games for the Astros in 2014, going 52-for-310 (.168). Baseball America regarded him as the Astros' best prospect by the end of the 2011 season.

Singleton's first positive test came in June 2012, his first month in Double-A, and he said he quit using marijuana for the rest of that season. After the season, during which he hit .284 with 21 homers and 79 RBIs, he went to the Arizona Fall League. He failed a second test in December 2012, with a 50-game suspension coming a month later. He was then admitted to an inpatient rehabilitation center for a month.

"I knew I had a problem," Singleton said in a 2014 interview with The Associated Press. "Even after I failed the second drug test, I couldn't stop smoking weed. It was really bad. Me going [to the rehab center] was definitely the best move."

He has also admitted to abusing alcohol as a substitute for marijuana after the stint in rehab.

General manager Jeff Luhnow declined to discuss Singleton's release on Tuesday.

The Associated Press contributed to this report.