For the season, he's hitting .337 with four homers, 15 RBIs and a .417 on-base percentage with Oklahoma City.
"I'm excited to be here and to help this team win some games," he said.
Grossman credited a 20-minute conversation he had with RedHawks hitting coach Leon Roberts in his office on the day he got sent down with helping him simplify things and get back to the basics.
"Keep it simple," Grossman said. "He played a long time and I think his track record speaks for itself. He just helped me like that and broke it down real simple and laid it out how I need to do."
Grossman, who started in left field on Opening Day for the Astros, is hitting .158 with a .273 on-base percentage for Houston this season.
Brian McTaggart is reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.