Martes returned in August and made two starts for the rookie level Gulf Coast Astros and one for Quad Cities of the Class A Midwest League. He was 0-2 with a 6.75 ERA in 5 1/3 innings.
Martes' ban isn't quite the Houston-related cheating punishment fans and players have clamored for around baseball. The Astros have been pummeled via the press by opposing teams since opening spring training, with many expressing disappointment that no players were suspended for their sign-stealing scam.
Martes did not have a statement, the players' association said.
"Throughout our system, players are educated through MLB's drug prevention and treatment programs," the Astros said in a statement. "We hope that Francis will learn from this experience moving forward."
He is the second player suspended this year under the big league program. Colorado pitcher Justin Lawrence was suspended for 80 games following a positive test for the performance-enhancing substance Dehydrochlormethyltestosterone (DHCMT). Lawrence also has yet to make his big league debut.