Rodriguez, 32, signed a one-year deal with the Brewers earlier this month. He has amassed a 3.15 ERA and 131 strikeouts in 125 2/3 innings during his 134 appearances with Milwaukee.
Roenicke said he's not sure how much Rodriguez has thrown during the offseason, but he's looking forward to getting him in camp.
"He's had a lot going on in his country," the manager said. "I don't know what he has done."
Jesse Sanchez is a national reporter for MLB.com. Follow him on Twitter @JesseSanchezMLB. This story was not subject to the approval of Major League Baseball or its clubs.