A guy to get at the deadline to really hurt the Red Sox: J.A. Happ. Red Sox have an OPS this year of .672 vs lefties, .813 vs righties. The other contending teams are all pretty much balanced in that regard. The usual suspects on the Sox have trouble with LHP (the LHHs), but also, surprisingly, JD Martinez. Nunez too. Hanley was .190 better OPS wise vs lefties this year, but he got canned. Some contender’s going after Happ, who has also pitched well over his career against the Red Sox.
Xander has hit about 30% better over his career vs L compared to R (128 WRC+ vs 96).
JD Martinez has been a career 143 WRC+ hitter vs L, compared to 130 WRC+ vs R.
Mookie has a career 137 WRC+ vs L, compared to 127 vs R. And he is killing lefties this year with a small sample size (52 AB) 221 WRC+.
Devers is a (short) career 109 wrc+ vs L, 92 WRC+ vs R.
Christian Vazquez has a career 85 WRC+ vs L, 67 WRC+ vs R.
Brock Holt has a 99 WRC+ vs L, 88 WRC+ vs R in his career.
With 4 of their top 6 hitters being better against lefties in their careers, and some of their back end of the lineup guys being better as well, I think they are going to end up just fine against lefties this year.