Fantasy baseball bullpen report featuring Mason Montgomery and Carson Seymour

Another week, and more volatility across the high-leverage landscape. While contenders push for the postseason, teams that are not will start auditioning players for next season, which benefits astute fantasy managers who focus on these situations rather than football.

Although his save total is not among the leaders in the second half, Mason Montgomery is amid his long-anticipated breakout as a closer. Don Kelly has not anointed him as such, but Montgomery has converted all four save opportunities since the trade deadline while not allowing a run in nine appearances in August, posting a minuscule 0.58 WHIP with 18 strikeouts and one walk (54.8 K-BB percentage) across 8.2 innings.

Small sample sizes can be misleading, but he’s been surging since the start of July, which coincides with introducing a sinker into his arsenal. In June, he used his sinker at a rate of 7.2%, but it rose to 28.1% in July and sits at 50.7% through the appearances cited above in August. For the visual crowd, here are his splits this season, by month and half-season, through games played on Aug. 26:

If his role as the preferred save option continues through the end of 2026, his fantasy stock for 2027 rises appreciably.

As the season progresses, it’s tougher to identify relievers on the rise, especially in bullpens with fluid roles. However, here are some interesting ones based on recent results:

Relievers on the rise

Juan Morillo (ARI): After his save on Aug. 26, he owns a 14-game scoreless streak, during which he has a win, the aforementioned save, and seven holds, while posting a 0.79 WHIP with 14 strikeouts versus three walks (21.2 K-BB%) over 14 innings. Whether he’ll remain the highest-leverage right-handed reliever or get more saves in September remains to be seen. In SOLDS leagues, it doesn’t matter.

Elvis Alvarado (ATH): He hasn’t been scored on in his past eight games, posting a 0.90 WHIP with seven strikeouts and two walks, recording a save in each of his past three. He teased fantasy managers after notching saves on June 10 and 13.

Erik Miller (BOS): Miller’s another reliever better suited for SOLDS formats or ones that count holds; however, he has turned in 10 scoreless outings since being acquired by the Red Sox. In that span, his WHIP is slightly below 1.00 and he’s recorded 18 strikeouts and three walks (35.7 K-BB percentage) through 10.1 innings.

Bradgley Rodríguez (SDP): Filling in capably for Jeremiah Estrada and Jason Adam as the Padres’ right-handed bridge option to Mason Miller, Rodríguez hasn’t allowed a run in 11 of his past 12 games, posting a 0.70 WHIP with 19 strikeouts and one walk (33.3 K-BB percentage) across 14.1 innings with a win, two saves and four holds.

On the other end of the spectrum, some concerns for closers as September nears:

Closer concerns

Yoendrys Gómez (MIN): He’s been listed previously, and regression came calling during a rough outing in Sacramento. There is no denying his fantasy appeal — he’s converted all 20 of his save chances this season. But the statistical migration toward the mean in the second half may not be over. His current 3.79 ERA is accompanied by a 4.63 SIERA and a more foreboding 5.32 xERA. Through 13.1 innings since the All-Star break, he has a 1.80 WHIP and a 16.1% walk rate; both are less than ideal for those trying to protect ratios down the stretch.

Riley O’Brien (STL): Although his manager insists his closer’s recent struggles are bad luck, O’Brien’s meltdown in Philadelphia — allowing four consecutive hits in two-strike counts — resulted in six earned runs and a walk-off loss. He recorded a 12-game scoreless streak before this happened, but he has also allowed at least a run in his past two outings, both losses. In the second half, he has recorded nine saves in as many chances. However, in these 14.1 innings, he has a 4.84 SIERA, which does not support the bad-luck narrative, a 6.1% swinging-strike rate, a 1.53 WHIP fueled by a 15.2 walk percentage, and an 80% contact rate allowed. His sell-high window has expired.

Stealth in September?

Luis Gastélum (STL): Segue alert: if one reliever is struggling, another could earn a larger leverage share in the final month of the season. Gastélum hasn’t been scored upon in seven of his past eight appearances, posting a 0.54 WHIP with 18 strikeouts and one walk (51.5 K-BB%) over his past 9.1 innings with a robust 21.7% swinging-strike rate. He’s definitely worth tracking.

Carson Seymour (SFG): Coming off a historic loss against the Reds, Tony Vitello should take a look at Seymour as his preferred save option going forward. Transitioning into a reliever has not been easy for Seymour, but he hasn’t allowed a run in six of his past seven appearances and recorded his first career save on Aug. 25. In his past 8.1 innings, he has 10 strikeouts and one walk (27.3 K-BB percentage) with a 14.2% swinging-strike rate. There may be a further learning curve, but his stuff and velocity grade better than Dylan Smith’s.

This leads into our updated leverage pathways, which aim to provide accurate team approaches for procuring saves despite the multitude of confusing usage patterns throughout the league. Each team will receive one of the following labels:

• Mostly linear: This is a more traditional approach, with a manager preferring one reliever in the seventh inning, another in the eighth, and a closer (when rested) in the ninth. There are shades of gray, but it usually follows a predictable pattern in high-leverage situations.
• Primary save share: The team prefers one reliever as the primary save option. However, he may also be used in matchup-based situations, whether dictated by batter-handedness or batting order, especially in the late innings. This provides multiple relievers with save chances each series or week throughout the season.
• Shared saves: Typically, two relievers share save opportunities, often based on handedness, rest, or recent usage patterns that keep them fresh. While these situations typically involve a primary and an ancillary option, other relievers may be used. Some teams also prefer a matchup-based option, which creates fluid save opportunities.
• Fluid: The manager has not named a closer, and usage patterns for the leverage roles remain unclear.

American League leverage pathways

Save streamers

*ancillary saves or shared roles

• Elvis Alvarado (ATH)
• Steven Cruz; Nate Pearson (KCR)
• Rico Garcia (BAL)
• Ryan Watson (LAA)

Save stashes

• Jeff Hoffman (MIN)
• Tyler Kinley (DET)

National League leverage pathways

Save streamers

*ancillary saves or shared roles

• Juan Morillo; Brandyn Garcia (ARI)
• Calvin Faucher; Josh Ekness (MIA)
• Daniel Duarte (NYM)
• Bradgley Rodríguez (SDP)

Save stashes

• Carson Seymour (SFG)
• Justin Martinez (ARI)
• Luis Gastélum (STL)
• Daniel Palencia (CHC)

Leaderboards

Saves

Holds

SOLDS

My rankings are a blend of in-season performance and rest-of-season expectations. If you feel strongly about a player, by all means, roster him.

Ratio relievers

*Multi-inning or bridge relievers who can vulture wins and help protect ratios.

• Juan Morillo (ARI)
• Erik Miller (SFG)
• Bradgley Rodríguez (SDP)
• Didier Fuentes (ATL)

Statistical Credits: FanGraphs, Baseball-Reference.com, Baseball Savant, BrooksBaseball.net. Check out my work at Reliever Recon and Closer Monkey for daily updates.