Blue Jays – Under-the-radar pitching prospects to keep an eye on after impressive starts to the season

Kai Peterson – LHP
Dunedin Blue Jays

A product of Citrus Heights, California, Peterson joins Munson and Rogers as a product of the 2023 MLB Draft and the southpaw has also found early success out of Dunedin’s bullpen.

Through 9 2/3, Peterson has allowed just three earned runs while striking out 19 batters, which currently leads the relief corps and sits second on the squad behind starter Fernando Perez. The left-hander owns a 17.7 K/9 to start the season which currently leads all relievers in the Florida State League (minimum 40 batters faced). He owns a 17.5% whiff rate and sits in the lower 90s with his fastball while mixing in a slider and curveball to opposing batters, who own a collective .147 SLG and a .503 OPS against the Blue Jays reliever.

Ryan Jennings – RHP
Vancouver Canadians

A product of the 2022 MLB Draft, right-hander Ryan Jennings has been the standout starter to begin the 2024 season for the Vancouver Canadians. Through three starts, he has allowed just one earned run while holding opponents to a .179 BABip and a .522 OPS with 13 strikeouts.

Of those starts, only one has seen Jennings allow more than one hit while he has found a way to limit opponents to a .143 average and limited the damage on the base paths to a 0.75 ERA, which ranks fifth in the Northwest League amongst starters with 3+ starts.

Grayson Thurman – RHP
Vancouver Canadians

Signed as a minor league free agent last spring, right-hander Grayson Thurman jumped past Vancouver late last year to make three relief appearances for New Hampshire but is starting the 2024 campaign on the West Coast. Through 7 2/3 innings, the 25-year-old owns a 2.35 ERA while striking out 11 batters through six appearances. Most impressively, he has not allowed a free pass this season, a vast improvement from the 4.8 BB/9 he posted last year.

Trenton Wallace – LHP
New Hampshire Fisher Cats

A member of the Blue Jays since 2021, left-hander Trenton Wallace has flown under the radar for quite some but continues to post solid numbers at each level he pitches at. Injuries limited him to just 12 starts last year but Wallace returns to the 2024 season healthy and leading the Fisher Cats starters right out of the gate.

Through four starts and 16 2/3 innings, Wallace owns a 2.16 ERA with a team-leading 23 strikeouts and a 1.26 WHIP. He hasn’t allowed an earned run in his last two starts and eight innings while allowing four or fewer hits in each outing. His hot start has lowered his professional career ERA to 2.54 with 203 strikeouts, a standout in the farm system who should be in triple-A by the end of the season if he continues on this trend.

Adam Macko – LHP
New Hampshire Fisher Cats

The most well-known prospect on this list, left-hander Adam Macko struggled in his first outing this year but has settled in nicely over his last three appearances. In total, he has allowed seven earned on the campaign while leading the Fisher Cats in terms of innings pitched (20.0) and sits just behind Wallace for the strikeout lead with 22 punchouts.

Macko owns a solid 1.10 WHIP and has limited opponents to a .289 OBP while striking out batters at a 9.9 K/9 rate and dropping his walk rate to a 3.6 value. The ceiling is high for the Vauxhall Jets alum, so much so that the Jays decided to add him to the 40-man roster this past offseason to protect him from the Rule 5 Draft.

Abdiel Mendoza – RHP
New Hampshire Fisher Cats

A product of Panama, this is Abdiel Mendoza’s third season in the Blue Jays organization after he was selected in the 2021 MiLB Rule 5 Draft from the Texas Rangers franchise. Mendoza finished the 2023 season in double-A, making four starts for the Fisher Cats, and the right-hander returns to the Eastern League for the 2024 season.

Through five appearances (one start), Mendoza has allowed just three earned runs through 14 innings (1.93 ERA). Much of this is due to his ability to generate ground balls, doing so at a 65.0% rate so far this season while getting opponents to pull the ball with increased frequency. With the ability to pitch bulk innings, Mendoza can also start as needed while giving the Fisher Cats relief should a member of the rotation elevate their pitch count early without burning through the bullpen.

Adrian Hernandez – RHP
New Hampshire Fisher Cats

For those who follow the Blue Jays prospect channels, Adrian Hernandez is likely a name you have heard over the years. He broke out in a big way in 2021 but struggled in triple-A in 2022 (4.96 ERA through 31 outings), prompting the Jays to send him back to New Hampshire for the 2023 season and now into the 2024 campaign.

Boasting some high spin rates and a top-notch changeup, Hernandez is off to a solid start in New Hampshire this season, making five relief appearances while allowing just six hits and one earned run across 7 1/3 innings. There’s still some finessing to be done with his walk rate, although the 4.9 BB/9 mark is a step in the right direction after posting an 8.5 BB/9 last year.

Luis Quinones – RHP
Buffalo Bisons

A member of the Blue Jays organization since 2019, Luis Quinones has worked his way up through the farm system and made three appearances in triple-A last year, a small sample size in the greater scheme of things. For his career, the Jays have used him as both a starter and a reliever, with the ability to pitch bulk innings, however, it now appears that role has shifted into a full-time reliever if the first month of the season is any indication.

Heading back to Buffalo, Quinones has made seven relief appearances through April and owns an impressive 2.40 ERA through 15 innings of work. He’s pitched 2+ innings in each outing except for his first appearance of the year (1 1/3) and has been able to limit the damage to just four earned runs off seven hits. In two of his outings, he allowed zero hits and zero runs while crossing the two-inning threshold, with 75% of his run total coming back on April 10th against Rochester. He can be wild at times, evident by his 10 walks on the year, but when Quinones is dialled in, he can be downright unhittable.

Zach Pop – RHP
Buffalo Bisons

While you can’t call Zach Pop a prospect anymore given he has 107 1/3 innings under his belt at the big league level, what he is doing in triple-A is outstanding and deserves some kudos.

The right-hander from Brampton, Ontario has three saves on the year and through 9 2/3 innings, he has allowed just two earned runs while holding opponents to a .205 average. With a nasty sinker that can reach the upper 90s on occasion, Pop still allows a few too many free passes but he finds ways to keep the runners on base, with his ERA sitting at 1.86 on the year. With a spot already on the 40-man roster, he is likely the next pitcher called up should the Jays need a bullpen arm in the near future.