Closer stock watch: O'Brien thriving in St. Louis

Perhaps we shouldn't be so surprised that St. Louis Cardinals RHP Riley O'Brien is thriving as a closer. He earned 15 saves for the 2023 Tacoma Rainiers in the hitter-friendly Pacific Coast League, with a 2.29 ERA and a 37% strikeout rate, inducing many ground balls and permitting only two home runs.

Those Seattle Mariners had a strong bullpen already, and O'Brien moved on to the Cardinals organization, where he thrived for Triple-A Memphis. He didn't make the Opening Day bullpen in 2025, but once he earned the big league chance, the numbers were good. O'Brien posted a 2.10 ERA and a 1.05 WHIP over 25⅔ innings after the All-Star break, saving six wins.

It seemed likely that O'Brien would save more games for this season's Cardinals and, after a few maiden appearances in earlier leverage roles, he moved to the ninth inning. Entering Tuesday, O'Brien boasts saves in four of his last six outings, permitting just one single (and hitting a batter) among the 20 batters he's faced in that span.

Ten pitchers have saved at least four games so far this season. Mason Miller is the only other to have permitted nary an earned run (Jordan Romano finally, painfully, left this special group on Monday). It is also hard not to notice a 75% ground ball rate, highest among right-handed relievers. OK, it's early and the Cardinals aren't great, but something is happening here.

Fantasy managers might have dismissed O'Brien in preseason drafts because he is, after all, a 31-year-old journeyman who, even while emerging last season, still issued quite a few walks. He doesn't exactly have a fancy strikeout rate, either. We tend to covet the overpowering strikeout options.

There are not many similarities between Miller and O'Brien. O'Brien's sinker averages 97.5 mph, and he throws the pitch 61% of the time, along with a slider. Still, he permitted only two home runs last season and, if he can continue to avoid walks this season, we have a legitimate fantasy option -- one who should keep accruing saves. While he is currently the most added relief pitcher in ESPN leagues, O'Brien nevertheless remains available in more than 50% of them. You know what to do.

Stock rising

Jakob Junis, RHP, Texas Rangers

Junis, 33, pitched well for the 2025 Cleveland Guardians, but doesn't every relief pitcher thrive on that team? A longtime starter who most fantasy managers ignored for good reason, Junis has never thrown particularly hard when compared to his peers, never piled on the strikeouts and, even last season, permitted nearly a hit per inning. He signed a one-year, $4 million deal in mid-January, giving "afterthought" with sixth-inning or long-man role vibes. Today, he leads the Rangers with three saves, one more than he accumulated during his first nine seasons combined.

This has happened because LHP Robert Garcia and RHP Chris Martin boast matching 1.83 WHIP marks, though achieved far differently. Martin has allowed 11 hits in six innings. Garcia has walked six in his six frames. Move on from them. Junis has permitted very little. RHP Cole Winn and LHP Jacob Latz are firmly in the picture, too, and they will get holds, but Junis -- I can't believe this has really happened -- might keep this role.

Gregory Soto, LHP, Pittsburgh Pirates

This one isn't as stunning, since Soto was twice an All-Star with the Detroit Tigers, although he wasn't much of a fantasy option during that time. Soto saved 30 games in 2022, but with a 3.28 ERA, a 1.37 WHIP and a 2-11 record. His career ERA is 4.19 with a 1.42 WHIP -- and that includes his solid early work for the Pirates, with only one run allowed (a Gunnar Henderson home run) and 13 strikeouts over 8⅔ innings.

Soto boasts only a single save (the same as RHP Dennis Santana), but there is clear pathway for both relievers to post some intriguing combination of at least 35 saves/holds. Santana was supposed to be "the guy," but now he is sharing things. We wouldn't say you are adding Soto to your teams with significant confidence, but he matters.

Paul Sewald, RHP, Arizona Diamondbacks

Unlike Soto, who always threw hard, Sewald, 36, hardly flashes "closer stuff." There is little question about his role, as he saved two more wins in Philadelphia this weekend, giving him five saves in eight appearances. Sewald and his 91.3 mph "heater" aren't really inducing myriad ground balls (early small sample caveats apply) and his swinging K rate remains far from where it was during his Mariners days. Still, opportunity is (mostly) everything.

Sewald will eventually walk a hitter and permit some home runs, but the path is clear for 30 saves. We should also mention that rejuvenated RHP Jonathan Loaisiga is the clear eighth-inning option and next in line for saves. Just like Sewald, he will eventually surrender walks and home runs but, for now, this surprising 1-2 duo can help fantasy managers -- especially those who remain stubbornly slow to buy in.

Stock falling

Edwin Diaz, RHP, Los Angeles Dodgers

Diaz will probably be fine -- nothing to worry about here -- but, alas, one rough outing from the weekend has people finally a tad concerned about his lowered fastball velocity. Diaz permitted an Evan Carter two-run home run against the Rangers on Friday. Then, still holding a one-run lead, singles to then-struggling Josh Jung and Ezequiel Duran helped blow the save. Max Muncy's third home run of the night gave Diaz the win, but it was ugly.

His four-seam velocity was at 97.3 mph last season (down from 99.1 mph in 2022) and it's 95.9 mph this season. The Dodgers will be cautious and LHP Alex Vesia closed out Saturday's win. Diaz could probably save 35 games on this loaded team with only half of a fastball, but watch this situation carefully. Lowered velocity is often a sign of injury. Vesia, rejuvenated LHP Tanner Scott (no walks!) and fried RHP Blake Treinen are all potential save options.

David Bednar, RHP, New York Yankees

Bednar is probably going to be fine, too, but what's with the 11 hits through 6⅔ innings, including multiple hits (and a run) in four out of five outings? We expected a 2.25 ERA, not a 2.25 WHIP! People forget it wasn't all that long ago that Bednar struggled mightily, losing the closer role in Pittsburgh several times during a frustrating 2024 campaign (5.77 ERA, 1.42 WHIP) before rebounding nicely last season and earning himself a trade to a contending team.

Again, BABIP should normalize (although it doesn't always) and fantasy managers shouldn't punt Bednar just yet, especially since setup RHP Camilo Doval (who has lost 2 mph off his own fastball) checks in with a 7.36 ERA. But, we remind you again, even the top relievers are volatile.

Trevor Megill, RHP, Milwaukee Brewers

Megill was on many fade lists for this season, as there seemed to be reason for concern for some combination of performance, health and role. The Brewers made it clear a potential saves timeshare with RHP Abner Uribe was possible. Well, Uribe still hasn't sniffed a save chance, but that might change after Megill permitted four runs in Friday's loss to the Washington Nationals, recording nary an out.

Megill entered the proceedings in a tie game and he soon untied it, though he was hardly hit hard. Megill plunked a guy. Then there was a bunt single, two other sacrifice bunts and an error. Uribe got hit harder on Sunday. Megill and Uribe lead the RP section of ESPN's most dropped list, but that's probably an overreaction. Roster Megill first, although I doubt he reaches 30 saves again.