Phillies Duo Struggling Mightily Against Fastballs This Season

Opposing pitchers are challenging and beating two Philadelphia Phillies hitters with fastballs.

Jul 23, 2024; Minneapolis, Minnesota, USA; Philadelphia Phillies third baseman Alec Bohm (28) and catcher J.T. Realmuto (10) celebrate after scoring runs against the Minnesota Twins in the ninth inning at Target Field. | Jesse Johnson-Imagn Images

The Philadelphia Phillies have been playing the best baseball in the MLB over the last three weeks since Don Mattingly took over as interim manager from Rob Thomson.

However, they are still far from a finished product. Now that they have climbed back over the .500 mark, if they want to remain there, areas of improvement do exist that they can maintain this elevated level of performance.

As noted by Matt Gelb of The Athletic (subscription required), 255 batters had at least 100 fastballs thrown to them in the strike zone entering play on May 17. That includes four-seamers and two-seamers.

If you went all the way to the bottom of the rankings, two Phillies players were present. Third baseman Alec Bohm had a slugging percentage of .222 on in-zone fastballs, which ranked 251st. A spot below him in the standings was catcher J.T. Realmuto, who had a slugging percentage of .211.

Alec Bohm, J.T. Realmuto struggling mightily against fastballs

Jun 12, 2023; Phoenix, Arizona, USA; Philadelphia Phillies catcher J.T. Realmuto (10) celebrates with first baseman Alec Bohm (28) after hitting a solo home run in the first inning against the Arizona Diamondbacks at Chase Field. | Matt Kartozian-Imagn Images

Bohm’s power stroke has been MIA since the second half of the 2023 season, when he earned a spot on the National League All-Star Team. He tore the cover off the ball in the first half but has been unable to replicate that production since.

Recently, he has started showing some signs of life at the plate. He has recorded an extra-base hit in three straight games; two to close out the series against the Pittsburgh Pirates and one to start a three-game set with the Cincinnati Reds.

Realmuto is showing a decline in the power department for the fourth consecutive season. Struggling against fastballs in the zone is a troubling development because it is an area he has thrived in the last few years despite diminishing returns at the plate.

The league average for slugging percentage on fastballs in the zone is .462. That is a number Realmuto has been at or above for four straight years coming into 2026, but is now nowhere close to matching.

Is age only factor in Realmuto's struggles?

May 14, 2026; Boston, Massachusetts, USA; Philadelphia Phillies catcher J.T. Realmuto (10) hits a single against the Boston Red Sox during the fifth inning at Fenway Park. | Eric Canha-Imagn Images

Pinpointing exactly what is wrong with Realmuto when facing fastballs is difficult. His swing speed has actually increased in 2026 from where it was in 2025, but outside of his whiff and strikeout rates, there isn’t much to get excited about when it comes to his batting profile at Baseball Savant.

Some regression when a player reaches their mid-30s is expected, as Realmuto turned 35 years old in March. But a fall off like this was certainly unexpected, especially considering how well he had been performing coming into the year.

Realmuto still provides elite value to Philadelphia with his defense behind the plate, but his offensive drop-off is concerning. Until he proves that he can handle fastballs in any capacity, expect opposing pitchers to continue challenging him with heat.

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