Blue Jays Prospect Weekly: Jake Casey's Power Surge, Johnny King Steps Up at Double-A
By Hannah Wells ·
Blue Jays Prospect Weekly covers the last 7 days of action for the Blue Jays farm system.
Four Bombs, Thirteen RBI: Jake Casey Is Doing Something Real
The week belonged to Jake Casey (A+, OF, Rank: 34). Across 25 plate appearances at High-A Vancouver, he hit four home runs, drove in 13, and added three doubles, producing the most jaw-dropping counting-stat line in the Blue Jays system this week. The raw damage was almost absurd for a player whose scouting projection sits at second-division outfielder with a 50 hit tool and 50 power grade. Those grades were written against a backdrop of modest early professional results, and Casey has been systematically dismantling that narrative since arriving at Vancouver. He entered the week with a .242/.372/.516 line and 10 home runs in 188 plate appearances at the High-A level, already punching well above his pre-season projection. The 13 RBI this week pushed his season RBI total to 45 in just 217 combined plate appearances, a rate that simply does not compute for a player penciled in as a depth outfielder ceiling.
The honest scouting tension here is real. His 61.2 percent contact rate is below average, and his swing rate has climbed to 48.8 percent over the last 30 days as the power has spiked, which means he is trading some zone discipline for impact. Over the last 30 days he is slashing .239/.339/.554 with seven home runs, so the contact suppression is showing up in the average while the slugging continues to scream. He is a plus runner with a plus arm, and if the power settles in as a legitimate above-average tool rather than a hot stretch, the profile transforms from depth piece into a genuine everyday candidate. He was a Tommy John rehab story with limited early professional exposure, and scouts had every reason to be conservative on the power grade. The question now is whether a 61 percent contact rate against High-A arms survives the jump to Double-A, or whether the power is a product of a short-to-impact swing that gets exploited when the breaking balls get sharper. What Casey has done this summer has already forced a reassessment of where his ceiling sits.
Johnny King is Flourishing at Double-A
Johnny King (AA, LHP, Rank: 4) pitched 8.2 innings in his second Double-A start, allowing three earned runs on four hits while striking out eight. The walk total, six, was a reminder that the command (graded 45) remains the ceiling-limiter in an otherwise legitimate mid-rotation profile. Still, his 2026 season is worth pausing on. He posted a 3.21 ERA with 112 strikeouts across 84 High-A innings before this promotion, and the Double-A ERA sits at 3.00 through two starts with 8 strikeouts against 6 walks in 9 innings. For a 20-year-old left-hander, those numbers are not a given. The 60-grade curveball is genuinely weaponized, and the four-seamer at 92-94 mph plays well at the top of the zone. His 34.7 percent whiff rate on the season is the calling card; he misses bats at a rate that most back-end starters cannot sustain at this age.
The six walks in 8.2 innings is not a small concern. His season walk total now sits at 56 in 93 innings, and the last 30 days show 16 walks in 21.2 innings at High-A, suggesting the command pressure that already existed got amplified as he worked against sharper hitters late in outings. The slider and changeup both grade at 50 and still need refinement to give him a reliable look against right-handed bats, and the long arm action creates mechanical risk that the organization will monitor carefully. But the foundation here is genuine: a young left-hander with a hammer curveball, a live four-seamer, and a strikeout rate that holds up across levels. The projection is a number-three starter, and the 8.2-inning Double-A outing, walks and all, did nothing to push back against that. The command is the last major variable, and until it settles, King remains a high-variance bet on a pitcher who already has the stuff to make the rotation ceiling look real.
Quick Hits
Sean Keys (AAA, 3B, Rank: 17) · went 9-for-29 with three home runs, a triple, and 9 RBI, pushing his Triple-A slash to .285/.409/.614 with 13 home runs in 193 plate appearances. The 60 power grade is doing exactly what it is supposed to do at this level; Keys has now hit 28 home runs combined across Double-A and Triple-A this season, with a .392 on-base percentage that gives the profile real teeth. The brief MLB stint (37 plate appearances, 13 strikeouts, .167 average) illustrated what happens when the 45 hit tool runs into execution-level pitching, but the production line he is building in the upper minors continues to challenge the second-division ceiling attached to his name.
Jake Cook (A, OF, Rank: 13) · delivered his best week of the season, going 11-for-30 with two doubles, two triples, two home runs, and 9 RBI. The outburst was eye-catching given his profile as a 55 hit tool, contact-first outfielder with light power (40 grade). Over the last 30 days he is slashing .284/.393/.514 with three home runs in 89 plate appearances, a power spike that has pushed his season slugging well above his projected output. His season walk total of 47 in 315 plate appearances reflects a genuinely patient approach, and the 55 speed and defensive versatility give him a multi-avenue path to value. Whether this power stretch represents a real adjustment or a hot month will be the defining question as he approaches a potential High-A assignment.
JoJo Parker (A+, SS, Rank: 1) · drew six walks and added six hits across 24 plate appearances, including two doubles and a triple, with 2 RBI. He has been the best prospect in the system all season and keeps proving it: over the last 30 days at Single-A Dunedin he was hitting .333/.432/.613 with four home runs, 20 RBI, and 12 walks in 88 plate appearances before his promotion to Vancouver. His combined 2026 line of .262/.394/.468 with 13 home runs, 25 stolen bases, and 70 walks across 437 plate appearances makes the 60 hit tool and everyday projection look conservative. The strikeout-to-walk ratio at High-A this week (9 Ks, 7 BBs in 38 PA at Vancouver) will be worth watching as the level stiffens.
Austin Smith (A+, OF, Rank: 45) · authored a remarkable line: 6 hits, three home runs, and 3 RBI across 28 plate appearances. His High-A numbers since arriving at Vancouver read .323/.380/.645 with five home runs in 72 plate appearances, a total departure from the .207/.348/.268 line he put up in 206 plate appearances at Single-A Dunedin. A 79 percent contact rate and very disciplined swing have always been part of the profile, and at High-A those traits are playing with more authority. The 45 power grade looks like it needs revisiting. His season strikeout total of just 41 across 278 combined plate appearances is among the best rates in the system.
Brandon Barriera (A, LHP, Rank: 30) · struck out five over three scoreless innings, allowing two hits and two walks. His last 30 days tell a more encouraging story than the full-season numbers: a 3.46 ERA across 13 innings with 21 strikeouts and a 38.4 percent whiff rate. That whiff rate is the reason the organization stays patient with him. The 55-grade slider is a genuine swing-and-miss weapon, and when his mechanics are on, the 93-95 mph fastball plays up. His full-season ERA of 4.82 at Dunedin reflects the 45 command and a 19-walk, 28-inning walk rate that is still too loose. Durability remains the overarching question; he has thrown only 30.1 professional innings across three-plus years before this season, and each clean outing matters.
Dasan Hill (A+, LHP, Rank: 5) · pitched 6.2 innings, allowing four earned runs on seven hits with eight strikeouts and three walks. The ERA on the season at High-A sits at 6.23 in 8.2 innings since joining Vancouver, and his combined 2026 mark is 5.87 across 53.2 innings. The 60-grade fastball at 97-99 mph and a 55-grade slider give him starter-quality stuff, and the 34.3 percent season whiff rate confirms he can miss bats. The command (45 grade) and pitch efficiency (20.6 pitches per inning) are the culprits keeping the ERA elevated; he has walked 42 batters in 53.2 innings this year. He is 20 years old with a potential all-star outcome on his scouting card, so the rough ERA is more a development marker than a verdict.
Josh Stephan (AAA, RHP, Rank: 42) · gave Buffalo six innings of two-run ball with seven strikeouts and one walk. It was his cleanest outing since joining the Blue Jays system, though the numbers remain a work in progress: a 6.00 ERA in 18 Triple-A innings with Buffalo, and a combined 5.52 ERA across 119 innings on the season split between two Triple-A stops. The sinker-slider mix and ability to generate weak contact are real when he keeps the ball down, and a long-reliever or swingman projection means he does not need to dominate every inning. A start like this one is the version of Stephan that makes the up-down path plausible.
Edward Duran (AA, C, Rank: 11) · was promoted to Double-A New Hampshire on August 18 and went 3-for-10 with two RBI and a stolen base in his first look at the level. The promotion caps a full-season journey that started at Single-A Dunedin. His High-A line of .231/.276/.331 in 181 plate appearances reflected a 53.7 percent swing rate that left him vulnerable and suppressed his walk totals, a notable regression from his 2025 full-season performance when he hit .296/.378/.439 at Dunedin. The plus arm (60 grade) and improving receiving give him a defensible everyday catcher ceiling, but the bat needs to stabilize at Double-A for the second-division projection to hold. The early sample at New Hampshire is encouraging at face value, small as it is.
Ryan Sprock (A+, C, Rank: 38) · drew four walks and added three hits including a double across 14 plate appearances, with 1 RBI. He is hitting .269/.402/.474 in 97 plate appearances at High-A Vancouver with a 50 hit tool and genuine zone feel; his season walk-to-strikeout ratio of 16 walks to 18 strikeouts at this level is a real skill. The up-down projection is grounded in modest power and a still-developing defensive profile behind the plate, but the contact and on-base approach have outpaced expectations at every stop this season.
Ricky Tiedemann (AAA, LHP, Rank: 7) · was recalled by Toronto on August 15, pitched 1.2 innings in his MLB debut appearance, then was optioned back to Buffalo the following day. His 2026 season has been fragmented across multiple levels as he works back, with just 4 innings at Triple-A and a 9.00 ERA before the call-up. The brief cup of coffee was a logistics move more than a statement; the development arc will be the story to watch as he builds innings.
Gage Stanifer (AA, RHP, Rank: 9) · posted three innings of one-run ball with four strikeouts in relief. It was a steadying outing after a brutal last 30-day stretch: an 8.00 ERA in 18 innings with 19 walks, 16 earned runs, and a 2.00 WHIP. The 60-grade slider and 95-96 mph fastball give the profile legitimate upside toward a fifth-starter or up-down role, but the command (45 grade) has been unraveling over the past month. His season ERA of 5.04 in 91 Double-A innings represents a significant step back from the 2.86 ERA he posted across three levels in 2025. A three-inning outing with one walk is at least a data point in the right direction.