Miller, one of the favourites in the discipline that takes in both downhill and slalom, is looking to become the first American to win an Olympic medal in the event.
After clocking one minute 38.91 on the Grizzly course, the provisional results suggest that he is on target to achieve that goal.
However, Miller faces stiff competition from Kjetil Andre Aamodt and Lasse Kjus, his main rivals for the title.
The two Norwegian veterans passed up the opportunity to train for the downhill section.
Wengen (Jan '02)
3. Kjus Kitzbuhel (Jan '02)
Miller has three World Cup slalom wins to his name this season and knows that if he is to beat the likes of Aamodt, who has won both combined events this season, and Kjus, that is where he has to make up the time.
"I'm not planning on going all out in this downhill," Miller said of his game plan for Wednesday's big event.
"I just don't have the experience on the skis to know what I can and can't do.
"But I'm really going to go for it in slalom.
Aamodt and Kjus will beat me in the downhill so I need to be going 100 percent to make up as much time on those guys in the slalom," he added.
Austria's Michael Wachoffer finished practice in second with AJ Bear of Australia in third.