One of the many players the Pittsburgh Pirates acquired throughout last offseason was left-handed reliever Mason Montgomery. He came over from the Tampa Bay Rays alongside Jake Mangum and Brandon Lowe. Montgomery showed plenty of potential last year, though he struggled in terms of the bottom line. However, while he is still running into some bad luck this season, he is showing even more promise.
Mason Montgomery Becoming a Reliable, But Unlucky Pirates Reliever
Montgomery Is Taking a Step Forward from Last Season
On the surface, his 4.14 ERA and 1.30 WHIP over 37 innings may not turn heads, but it is a sizable step forward from the 5.67 ERA and 1.60 WHIP he had in 47 IP last year. The surface-level stats aren’t the only areas in which Montgomery has gotten better. He has also improved in multiple other peripheral measurements compared to his 2025 campaign.
Last year, the lefty struck out 30.1% of opponents but has upped that to 34.8% this year. He has also reduced his walk rate from 12.9% to 10.8% between 2025 and 2026. Montgomery is inducing many more ground balls. His GB% went from under 45% with the Rays in 2025 at 43%, up to 50.6% this season. Montgomery is locating his pitches much better. FanGraphs’ Location+ metric put him at 91 last year, but it is now up to 103.
He is also well above average in many other metrics. His whiff rate sits in the 88th percentile at 31.5%. He has a sub-3.00 SIERA, FIP, and xFIP at 2.77, 2.91, and 2.71, respectively. Last year, he owned a 3.92 FIP, 3.55 SIERA, and 3.56 xFIP. xERA has seen the most improvement for Montgomery, going from 4.57 last year (22nd percentile) to 3.22 this season (81st percentile).
Recent String of Bad Luck
Even though these numbers are all very promising, many unlucky factors are working against Montgomery. Since the start of June, he has a .393 batting average on balls in play. In that time, he still has a 29.5% K-BB%. Montgomery added a curveball this season. Opponents have a .382 wOBA and a .542 slugging percentage against his curveball, but it is one of the unluckiest pitches of its kind in baseball this year.
A New, High-Quality, But Unlucky Pitch
106 pitchers have thrown a curveball at least 100 times this year. The 75-point difference between the wOBA (.382) and xwOBA (.307) is the 14th highest difference. There is also a 129-point difference between the slugging percentage (.542) and xSLG% (.415) opponents have against his curve. Montgomery is one of only 18 pitchers with a whiff% over 40% with their curveball. He sits at 40.9%. FanGraphs’ Stuff+ metric also rates his curveball highly, at 120. It is the seventh highest mark of any lefty pitcher who has thrown at least 30 IP this season.
A Potential Savior For The Pirates’ Bullpen
The Pirates’ bullpen has struggled in general this year. Hopefully they add a few arms at the trade deadline, but Montgomery could be one of their saving graces as well. Among all the Pirates’ hurlers who have thrown at least 30 innings this year, Montgomery has the 2nd best FIP, the best xFIP, and the best SIERA. His K-BB% of 24.1% is tied with Paul Skenes for the team lead. His 28.9% called swinging strike rate is the fourth best on the Pirates, and he is the only Pirates pitcher with a sub-70% contact rate at 69.9%.
Montgomery’s Outlook for the Rest of the Season
Montgomery will turn things around this year. His new curveball is too good not to turn things around on its own eventually, and all his other metrics suggest he is doing significantly better in 2026 than he did in 2025. By the end of this season, he could be one of the Pirates’ go-to answers late and in close games.
Main Photo Credits: Rafael Suanes-Imagn Images
