Grossman, recovered from the ankle injury, returned to the top of the order for Saturday night's game against the Texas Rangers. But Gonzalez, who was scheduled to bat seventh, had to be pulled from the lineup because of a tight hamstring.
"I think it's just a one-day thing," Porter said of Gonzalez. "It's just a little bit tight. He's been playing really well and we don't want to risk anything moving forward. We'll give him the day, let him get treatment and hopefully [Sunday] he will be ready to go."
Gregorio Petit replaced Gonzalez in the starting lineup Saturday night. Gonzalez is 8-for-17 on the Houston homestand and has raised his average to .272.
"I've been feeling good when I play," Gonzalez said. "I'm being more selective, trying to be more patient at the plate. I've been seeing a lot of pitches, five or six pitches an at-bat."
"He's been swinging the bat well from both sides of the plate," Porter said of Gonzalez. "Putting him in [the leadoff] spot he was finding the holes and played well. Marwin's done a great job."
Gonzalez said he had batted leadoff in the Minors and also for a short time with the Astros in 2012.
"It's normal," he said. "I'll bat any place. I just want to be in the lineup. It doesn't matter if you're hitting ninth, eighth or leadoff."
Gene Duffey is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.