Yelich's OPS is all based on his extremely high walk percentage which probably is unsustainable if he continues to slug below .400. I don't know what is going on with him but his mechanics look completely messed up; he seems to not be bending his front knee properly which might mean he never recovered from fouling the ball off the knee. It was a fracture of his knee cap which healed on its own without surgery. At worst he would have had to wear a locked brace on his leg for 6 weeks. Yelich is still a good baserunner, and is never described as "lumbering" which one would expect if there were any lingering issues. His fractured patella has nothing to do with his current performance. Rather, take a look at Yelich's career line before he was traded to Milwaukee .290/.365/.406. Since the end of 2019 his OBP is .379 and his Slugging is .410 right in line with his Miami numbers. It just might be who he is: high on-base percentage, and more of a doubles/triples hitter than a player who will regularly stroke 35+ homeruns a year. His production in 2018 and 2019 certainly appear to be outliers and likely will be the two best of his career. That would be very bad. The Brewers aren't paying him to be a high OBP and doubles/triples hitter. They trusted his 2018 and 2019 enough to give him that massive deal and if this current version of Yelich is what we are getting going forward then this is a major bust of a contract.