Red Sox Bullpen Overhaul: Southpaws Dominate as Matz Joins the Fray

As of July 31st, 2025, the Boston Red Sox have made a significant move to bolster their bullpen, acquiring left-handed pitcher Steven Matz from the St. Louis Cardinals. This trade comes a year after left-handed relief pitching was a constant concern for the Red Sox.

Prior to the trade deadline, the Red Sox already had a strong left-handed presence in their bullpen, with closer Aroldis Chapman, Justin Wilson, Brennan Bernardino, and Chris Murphy all contributing from the southpaw side. However, the addition of Matz has now made the Red Sox bullpen 62.5% left-handed, which may not be the optimal strategy, as most hitters in Major League Baseball are right-handed.

The Red Sox will likely need to make a roster move to accommodate Matz, and speculation suggests that Bernardino, who has been a workhorse for the team this season with 47 appearances, may be the one sent down to the minors. Bernardino has been impressive, posting a 3.09 ERA and 36 strikeouts in 43 1/3 innings, but the Red Sox may feel the need to balance their bullpen with more right-handed options.

Meanwhile, Chris Murphy, who has made 10 appearances since his Tommy John surgery recovery, has also been effective, with a 2.70 ERA and 14 strikeouts in 16 2/3 innings. Both Bernardino and Murphy are expected to play important roles for the Red Sox down the stretch, but the arrival of Matz has created a roster crunch that the team will need to address.