Cooper Hjerpe - MLB News, Rumors, & Updates

Cardinals' top 10 moments of 2026, No. 8: Cooper Hjerpe perfect in long-awaited debut It's crazy that Hjerpe's debut wasn't even the best of the season!

OCTOBER 4 • REDBIRDRANTS.COM

Cardinals Demote Cooper Hjerpe in Surprise Move With 3 Games Left The St. Louis Cardinals are sending Cooper Hjerpe down.

SEPTEMBER 24 • SI.COM

Cardinals option Cooper Hjerpe for fresh arm after exciting start to MLB career What a fun opportunity it was to see Cooper Hjerpe pitch this season.

SEPTEMBER 24 • REDBIRDRANTS.COM

Optioned after final bulk outing The Cardinals optioned Hjerpe to Triple-A Memphis on Thursday, Derrick Goold of the St. Louis Post-Dispatch reports.

Impact Hjerpe made his final appearance of the season in Thursday's loss to the Pirates, tossing 3.1 shutout innings in a bulk relief outing. The Cardinals will announce a corresponding roster move prior to Friday's game in Milwaukee. Hjerpe made four appearances for the big club as a piggyback partner with Kyle Leahy, logging a 4.27 ERA and 15:9 K:BB over 12.1 innings. The left-hander will likely compete for a spot in the Cardinals' Opening Day rotation next season.

SEPTEMBER 24 • ROTOWIRE

Set for another piggyback outing Hjerpe is expected to work as a piggyback pitcher behind starter Kyle Leahy in Thursday's game against the Pirates.

Impact Since being called up from Triple-A Memphis on Sept. 6, Hjerpe has made all three of his appearances to date as part of a piggyback tandem with Leahy, whose workload the Cardinals are deliberately looking to keep in check as the season winds down. The rookie left-hander has had mixed results thus far, going 1-0 with a 12:6 K:BB while yielding six earned runs and giving up four hits across nine innings.

SEPTEMBER 24 • ROTOWIRE

Rough performance in second game Hjerpe allowed four runs on two hits, four walks and two hit batsmen while striking out three over one-plus inning of relief in a no-decision versus the White Sox on Saturday.

Impact Hjerpe wasn't able to replicate his four perfect innings from his big-league debut in Colorado last weekend. The southpaw will remain on a starter's schedule while working in tandem assignments with Kyle Leahy to close out 2026. That spot in the rotation is set to come up again at home versus the Nationals, and if Hjerpe continues to be the bulk reliever, he will be in better position to collect wins.

SEPTEMBER 13 • ROTOWIRE

Grichuk hits a 9th inning HR to help White Sox beat Cardinals 6-5

Randal Grichuk hit a two-run homer in the ninth inning, helping the Chicago White Sox break a four-game losing streak with a 6-5 win over the St. Louis Cardinals

SEPTEMBER 13 • Associated Press

Staying on starter's schedule Hjerpe will remain on a starter's schedule for the Cardinals down the stretch and is currently penciled in to serve in a piggyback role with Kyle Leahy, Derrick Goold of the St. Lo...

Impact Hjerpe made his major-league debut last week in Colorado, striking out six over four perfect innings out of the bullpen behind Leahy. The lefty remains on the active roster but will not be available out of the bullpen in between his scripted appearances. A good close to the 2026 season could enhance Hjerpe's chances of breaking camp next year as a member of the Cardinals' rotation.

SEPTEMBER 9 • ROTOWIRE

Cardinals Set Expectations For Cooper Hjerpe After Impressive Debut With injuries piling up down the stretch, the St. Louis Cardinals turned to 25-year-old Cooper Hjerpe in the bullpen, and his debut on Sunda...

SEPTEMBER 7 • SI.COM

Cardinals' Cooper Hjerpe joins elite St. Louis company with debut perfection The southpaw was excellent against Colorado.

SEPTEMBER 7 • REDBIRDRANTS.COM

Move Over Max Scherzer: Cooper Hjerpe's Perfect Cardinals Debut Makes History The St. Louis Cardinals' lefty made his big league debut on Sunday and was amazing.

SEPTEMBER 7 • SI.COM

Deadspin | Cardinals storm past Rockies thanks to big inning, Cooper Hjerpe's debut Deadspin | Cardinals storm past Rockies thanks to big inning, Cooper Hjerpe's debut

SEPTEMBER 6 • DEADSPIN.COM

Stellar out of bullpen in debut Hjerpe (1-0) struck out six over four perfect innings of relief to earn the win over the Rockies on Sunday.

Impact Hjerpe entered the contest in the fourth inning and set down 12 straight Rockies on a total of 54 pitches (41 strikes). Big-league debuts don't get much better than that. Across four levels of the minors this season, Hjerpe posted a 3.00 ERA, 1.26 WHIP and 61:32 K:BB over 42 innings as he worked his way back from Tommy John surgery. Hjerpe is poised to serve as a piggyback option as the Cardinals cut Kyle Leahy's innings back down the stretch. The duo could work as a tandem for likely three more turns through the rotation, with the next one tentatively projected to be at home versus the White Sox next weekend.

SEPTEMBER 6 • ROTOWIRE

Herrera and Hjerpe lead Cardinals to a 10-8 win over the Rockies

Iván Herrera had three hits and two RBIs, Cooper Hjerpe threw four perfect innings of relief in his major league debut and the St. Louis Cardinals held on to beat the Colorado Rock...

SEPTEMBER 6 • Associated Press

Cardinals reward resilient 2022 1st round pick Cooper Hjerpe with Major League debut Get ready for that fun delivery!

SEPTEMBER 6 • REDBIRDRANTS.COM

Promoted Sunday The Cardinals recalled Hjerpe from Triple-A Memphis, and he is expected to pitch behind starter Kyle Leahy against the Rockies on Sunday, Jeff Jones of the Belleville News-Democrat...

Impact Hjerpe was promoted from Double-A Springfield to Triple-A in early August, and he posted a 0.95 ERA, 1.42 WHIP and 27:17 K:BB across 19 innings in his first five starts for Memphis. Leahy has failed to last five frames in each of his past two starts but has given up two runs or fewer in each of his past 12 outings, so Hjerpe could have a decent chance at a win if Leahy has another short but effective start Sunday.

SEPTEMBER 6 • ROTOWIRE

Activated from 60-day IL Hjerpe (elbow) was activated from the 60-day injured list at Double-A Springfield on Thursday.

Impact Hjerpe had Tommy John surgery last April and has completed a rehab assignment, allowing four runs with a 9:3 K:BB over 8.2 innings covering five starts between Single-A Palm Beach and the rookie-level Florida Complex League. The left-hander struck out four over three scoreless frames in the FCL his last time out and will continue to get stretched out in the Springfield rotation. Hjerpe is on the Cardinals' 40-man roster and should move up to Triple-A Memphis before long if he's pitching well. A major-league debut during the second half is possible.

JULY 2 • ROTOWIRE

Kicking off rehab assignment Hjerpe (elbow) will begin a rehab assignment at the Cardinals' Florida Complex League affiliate Friday.

Impact It will be Hjerpe's first game action since he underwent Tommy John surgery last April. The left-hander will knock off some rust in the FCL before eventually moving up either to Double-A Springfield or Triple-A Memphis. Hjerpe is on the Cardinals' 40-man roster and could push to debut at some point in the second half. The former first-round pick collected a 3.27 ERA, 1.13 WHIP and 76:28 K:BB in 52.1 innings at Springfield in 2024.

JUNE 5 • ROTOWIRE

Cut from big-league camp The Cardinals optioned Hjerpe (elbow) to Triple-A Memphis on Monday.

Impact Hjerpe just recent resumed throwing from the mound following last April's Tommy John surgery. A former first-round pick, Hjerpe is aiming to make his season debut around midseason.

MARCH 9 • ROTOWIRE

Throws bullpen session Hjerpe (elbow) threw a bullpen session Tuesday, Daniel Guerrero of the St. Louis Post-Dispatch reports.

Impact It's the first time he's thrown from the mound since last April's Tommy John surgery. Hjerpe is aiming to make his season debut around mid-July. The left-hander collected a 3.27 ERA, 1.13 WHIP and 76:28 K:BB in 52.1 innings at Double-A Springfield in 2024.

FEBRUARY 25 • ROTOWIRE

Aiming for mound work next week Hjerpe (elbow) is aiming to throw a bullpen session next week, Jeff Jones of the Belleville News-Democrat reports.

Impact Hjerpe played catch off the mound Monday, but a bullpen session next week would be his first since last April's Tommy John surgery. The left-hander was added to the Cardinals' 40-man roster over the offseason and is on track to return to game action around midseason. Hjerpe has collected a 3.38 ERA and 127:53 K:BB over 93.1 innings since St. Louis took him in the first round of the 2022 First-Year Player Draft.

FEBRUARY 16 • ROTOWIRE

Joins 40-man roster The Cardinals selected Hjerpe's (elbow) contract from Double-A Springfield on Tuesday, John Denton of MLB.com reports.

Impact Hjerpe is expected to miss the first portion of the 2026 season after undergoing Tommy John surgery in April, but the Cardinals will grant him a 40-man spot anyway to ensure he doesn't get selected by another club during the Rule 5 Draft. The 24-year-old lefty owns a 3.38 ERA and 1.18 WHIP across his minor-league career and will presumably return to Double-A once he's deemed fully healthy.

NOVEMBER 19, 2025 • ROTOWIRE

Undergoes Tommy John surgery Double-A Springfield transferred Hjerpe (elbow) from the 7-day injured list to the full season injured list Tuesday.

Impact Hjerpe recently underwent season-ending Tommy John surgery, which is certainly notable after the 24-year-old dealt with elbow issues last season and didn't pitch after July 2. He was given a clean bill of health over the offseason, but he'd yet to pitch in the minors early on this season. Hjerpe will miss another full season and has been limited to just 93.1 innings since being selected in the first round of the 2022 Draft.

APRIL 15, 2025 • ROTOWIRE

Out with undisclosed injury Double-A Springfield placed Hjerpe on the injured list with an undisclosed injury, Sam Dykstra of MLB Pipeline reports.

Impact He's missed a lot of time with elbow injuries since getting drafted in the first round of the 2022 First-Year Player Draft. Hjerpe's inability to handle a starter's workload thus far points to a future in relief. He had a 3.27 ERA, 1.13 WHIP and 76:28 K:BB in 52.1 innings (15 starts) at Double-A last year.

APRIL 4, 2025 • ROTOWIRE

Clean bill of health this spring Hjerpe (elbow) allowed one run over an inning of work in his Grapefruit League debut Tuesday versus the Blue Jays.

Impact Hjerpe didn't pitch after July 2 last season due to left elbow inflammation, but he had a normal offseason and entered Cardinals camp with a clean bill of health, Daniel Guerrero of the St. Louis Post-Dispatch reports. The lefty has had elbow issues in each of his two pro seasons and changed his diet this offseason with the goal of reducing inflammation and soreness in his body. Hjerpe had a 13 percent walk rate but also a 35.2 percent strikeout rate in his 52.1 innings between High-A Peoria and Double-A Springfield in 2024. He'll rejoin the Springfield rotation for the start of the 2025 campaign as he hopes to stay healthy and cut down on the free passes.

FEBRUARY 27, 2025 • ROTOWIRE

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Grichuk hits a 9th inning HR to help White Sox beat Cardinals 6-5

Herrera and Hjerpe lead Cardinals to a 10-8 win over the Rockies