What does one have to do with the other? And Brentz was exactly where he was needed: as a decent bat in AAA. An .863 OPS at age 28 is hardly impressive, and is barely AAAA territory. There's exactly nobody on the MLB roster that couldn't put up similar numbers in the minors, so there was less than a zero chance that he'd have been an upgrade anywhere. Brentz doesn't have the plate approach needed to stick, or even help, at the MLB level.
1) You misinterpreted what I was saying. I never said either player should have been in the majors. I was just saying it's frustrating to have such tantalizing power just out of reach (for different reasons) when our team leader hit 24 HR and we had a whopping four guys hit 20.
2) But since you raised it... This is Brentz's best season in AAA, but he had "full" season OPSs there of .788 and .806 in 2013 and 2014, with a combined 29 HRs in 616 PA. His issue has really been health. Games played over the previous 4 seasons are 88, 72, 59, and 91. Maybe the toe tap has been the reason for his improvement this year or maybe he's back to full health, maybe a little of both. It's possible (maybe even probable) this is his high water mark, but he's still a useful piece at the 2013-2014 level. It's not like he's come out of nowhere at 28, though. He was a decent prospect until he couldn't stop getting hurt.
3) I don't do MLEs; nor do I know of a quick and dirty calculator. But ZiPs projected a .696 OPS (which is right around his .690 OPS in his robust career sample of 90 PA) for Brentz at the ML level this year - before the best season of his career. Even if he were to hit only that, that's better than 10 of the 22 position players who had ABs for the Red Sox this year. By my count, there are 6 players on the 40-man plus Pablo Sandoval and Steve Selsky who actually had at least 25 ABs in AAA and couldn't manage an OPS within .100 of .863. And in those combined 1290 ABs they hit the same number of HR Brentz did in 2017.
4) What about his approach disqualifies him from being useful at the ML level? He's no Mookie Betts in his approach, but some comparisons:
2017 Bryce Brentz: 22.1 K%, 8.5% BB%, 0.39 BB/K, 1.19 GB/FB, 3.79 P/PA.
AAA Bryce Brentz (roughly 3 seasons' worth): 24.2 K%, 8.0 BB%, 0.33 BB/K, 1.28 GB/FB, 3.77 P/PA.
2017 Red Sox: 19.3 K%, 9.0 BB%, 0.47 BB/K, 1.32 GB/FB, 3.95 P/PA.
2017 Jackie Bradley: 22.9 K%, 8.9 BB%, 0.39 BB/K, 1.50 GB/FB, 3.76 P/PA, 1.9 bref oWAR.
I was not insinuating Brentz or Chavis should have been in the majors in 2017 with my original post. However, Bryce Brentz should have been a September call-up, and I hope he gets a real shot with the Red Sox in 2018 before he's cast off and is useful as a 4th or 5th OF for someone else for the league minimum.