Well yes, I don't think he had a brain injury that would make him forget how to do baseball. I think the Brewers are pretty comfortable with that. I would suspect he may be limited at least early in spring training but again, he isn't the first person to undergo these surgeries and they are most likely being done by preeminent doctors with top notch rehab. He isn't going down to the local strip mall to recover. At the end of the day the only factual position is that the Brewers have far more insight, medical and otherwise, into Winker than any of us schleps so I'll go with their evaluation.
The results from Yelich are much more likely due to a chronic back issue than the knee. Unless you have definitive proof that this version of Yelich is a direct result of a knee injury...