If his role will be to only start vs LHPs in LF or DH, then his numbers look good, but who will he start for? We can see now how Young, one of MLB's best hitters vs LHPs over the last 3-4 years, is being squeezed out of playing time. If Pedey wasn't injured, I doubt Young would play over Nunez, HRam or Beni vs LHPs.
Also, we always go into these things looking for someone who kills lefties, and then we end up playing them ve RHPs more than we wanted due to injuries. Sometimes, it works (Cody Ross), sometimes it doesn't all that well (Gomes struggled at times as Young has this year).
I'm not against giving Brentz a shot at the 4th OF slot next year, in fact, I'm not for signing an OF'er this winter, but maybe a guy like Nunez, who can play LF, if needed.
Better stat: OPS splits vs RHP/LHP
Brentz in minors
2017 .850/1.035 AAA
2016 .621/.930 AAA and .690/.598 AA
2015 .656/.767 AAA
2014 .698/.765 AAA
2013 .789/.785 AAA