Im going to throw out the Altuve extension as a comparable for Yelich. Altuve was a year or so younger than Yelich, and had only two years left on his deal (compared to Yelich with three). But before the 2018 season, he signed a 5 year/$151M extension to take him through his age 34 season. So, roughly $30M a year. Now, you can argue that Yelich is more impactful or whatever - but it's just a rough comparison. You can also argue that Yelich is worth more - closer to the $35M that Arenado and Trout are getting. And that's probably true. But getting a new contract three years before the existing one expires requires some give back to the Brewers. In the end, I think it would be something like $30-32M. But that's just my guess. The knee cap injury might make Yelich more inclined to consider such an extension. One injury can derail a career - and locking in extra $150-160M isn't a bad thing to do.