"It felt like a big cramp when I was running down to first," Miller said. "Obviously I felt it pretty good. I knew I probably wouldn't be able to keep playing. It's still sore obviously, but it's feeling better each day. So hopefully as soon as I can, I'll get back out there quick."
Manager Eric Wedge sounded a more cautious note, however.
"He felt good today and he's going to take some swings in the cage, but he's still not doing anything from the running standpoint," Wedge said. "I still think he's days away. How many days, I don't know."
Miller said his leg felt fine prior to the bunt attempt and he doesn't remember having any hamstring issues before.
"It's just something that got a little tight on me," he said, "but it's nothing too crazy. They said the strength is there, so hopefully it was just a big cramp and now it's just sore."
With Miller sidelined, fellow rookie Carlos Triunfel got his second straight start at shortstop on Monday.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.