"I've only pinch-hit, and it's hard to get your timing down doing that," he said. "I'm excited to get in there for the game."
Martinez, who entered Friday hitting .254 with seven homers and 36 RBIs, said several weeks ago he felt it would be important for him to play winter ball this season to try to make up for lost time and put up some numbers to impress Astros management.
He said Friday he's 95 percent sure he'll play this winter in either the Dominican Republic or Venezuela.
"I just feel that it's good for me to go," he said. "I missed a lot of at-bats, and at the end of the day, I'm still young and still could see myself maturing. I don't feel like I've peaked out this year where I don't feel there's nothing to learn. I could still learn."
Brian McTaggart is a 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.