"It's really hard when you get someone from another country and I can't have [direct] communication with him," Roenicke said Saturday. "I miss a lot going through an interpreter. I really don't get an idea at all what this guy's got upstairs. The conversations are too difficult to understand.
"He's young, and you're not sure what's going on upstairs."
Wang, 21, was plucked from the Pirates in the Rule 5 Draft and must remain on the Brewers' active roster all season or be offered back to Pittsburgh.
The Brewers already have one left-hander, Will Smith, in the bullpen. Tom Gorzelanny will join Smith when he fully recovers from offseason shoulder surgery. Non-roster invitee Zach Duke is also making a push for a job.
When it comes to Wang, the decision will be all about what the Brewers anticipate from him on the mound.
"It will just be the visual on what we see and how he handles the big setting," Roenicke said. "We'd actually like him to get hit a little to see how he reacts."
Wang has not allowed a run in 7 1/3 innings this spring. Opponents are hitting .192 against him.
Chris Gabel is a contributor to MLB.com. Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. This story was not subject to the approval of Major League Baseball or its clubs.