"It takes away some of your body weight," Smith said. "I started at 50 percent of my body weight and got to 75 percent of my body weight. That's why I'm staying here, so I can keep using that treadmill."
The Brewers' head physician, William Raasch, has a similar machine at his practice, Smith said. He will work out there throughout the Brewers' trip, which begins in St. Louis on Monday and continues to Pittsburgh and Minneapolis. The team returns home on April 20 against the Twins.
The original plan, according to Smith, was rest and rehab for four weeks before reassessing the strength of his knee to determine whether surgery is necessary. A surgical procedure would end his season, but there remains hope he will be able to resume pitching without a repair.
"So I'll hang back. It's going to stink not being with the guys," Smith said. "I'm moving around real well. It's a little sore in the morning, but I think that might just be the cold weather. Once everything gets moving, I'm fine."
Two other pitchers on the disabled list, starter Matt Garza (lat strain) and reliever Corey Knebel (oblique strain), will travel with the team.
Adam McCalvy is a reporter for MLB.com. Follow him on Twitter @AdamMcCalvy, like him on Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.