Portland Sea Dogs left-handed pitcher Miguel “Mickey” Pena was suspended for 100 games after testing positive for a banned substance for a third time, the Office of the Commissioner of Baseball announced Monday.

Pena, 23, was 2-2 with the Sea Dogs with a 6.41 ERA. He was scheduled to start again Wednesday in Erie, Pennsylvania, where the team began a three-game series Monday.

Neither Red Sox farm director Ben Crockett nor the Sea Dogs front office could be reached for comment.

This is Pena’s second suspension. He received a 50-game ban on April 17, 2013 for his second positive test. It is not known when the first positive test was because the commissioner’s office normally issues a warning for the first positive test for a “drug of abuse,” which is not considered a performance-enhancing drug.

According to the official Minor League Baseball website (milb.com) “drugs of abuse” include “marijuana, cocaine, heroin, LSD, ecstasy and other opiates.”

Pena, from Mission, Texas, was a sixth-round draft pick in 2011. After his suspension in 2013, he came back to pitch for advanced Class A Salem, before being promoted to the Sea Dogs on Aug. 20.

He made 13 starts for the Sea Dogs this year.

Pena’s latest suspension begins immediately.

Sea Dogs Manager Billy McMillon had no comment on the suspension after Portland’s 8-7 loss to Erie on Monday.