Future Stars on the Mound in MLB

Today is my 10th anniversary with my wife, so this afternoon I will be logging off for the day and spending a night away with my wife with zero kids. I had to get some writing in this week after grinding on the dynasty and prospect rankings. Check those out here:

Pitchers dominated yesterday. Let’s break down all those who dominated across the minors.

Minor League Standout Pitchers

Quinn Mathews, LHP, St. Louis Cardinals, 24, AAA

Mathews went from a low-90s innings-eating arm out of Stanford, who went in the fourth round in 2023, to one of the top pitching prospects in baseball very fast. After sitting 91.5 mph at Stanford, Mathews averaged nearly 95 mph last year.

From a performance standpoint, Mathews struck out 202 batters across four levels in 143 innings pitched, lapping the field on his way to the MiLB strikeout crown in 2024. A shoulder injury derailed Mathews early in 2025, and if you look at the surface numbers this year, they aren’t great and largely affected by the injury. While Mathews has a 3.63 ERA in Triple-A across 62 innings, he also has a 1.58 ERA and an 18 percent walk rate.

The last two starts have really seen Mathews take a step forward, and last night Mathews tossed seven scoreless innings with just two hits and one walk while striking out nine batters. He generated 21 whiffs on the start and had a 36 percent CSW.

The fastball ticked up, as previously mentioned, but it can reach 98 with 17 inches of IVB, which is above average from his 5’7” release height. Mathews gets a solid extension and had an impressive whiff rate on the fastball.

The changeup has heavy arm-side movement, around 81 mph, his highest whiff rate offering of any pitch. It generated 13 whiffs on 22 swings last night. The slider has also been a solid secondary, showing a good movement profile and sitting around 85 mph. Mathews rounds out his arsenal with a two-plane curveball in the mid-70s, giving him four true velocity bands.

When you pair an above-average strike thrower with a major tick-up in stuff, you have the makings of a high-floor arm. The command has taken a huge step, and Mathews’ strike rate sits at 56 percent on the year. The encouraging thing is that last night his strike rate sat at 69 percent. Hopefully, it is a catalyst moving forward as Mathews is fully healthy.

Robby Snelling, LHP, Miami Marlins, 21, AAA

The move to Triple-A has seen Snelling blossom, and he looks like one of the best arms in the minors. Snelling punched out 11 batters over six scoreless innings, allowing five hits. It was the second time in three starts we have seen Snelling strike out 11 batters. He generated 24 whiffs last time out and 22 whiffs last night.

When you look at Snelling, his strong frame probably does not scream premium athlete. But he is an exceptional athlete who was a four-star linebacker recruit, heading to LSU for both baseball and football. He spent little time focusing on baseball alone until being drafted. While 2023 was incredible, 2024 was a step in the wrong direction as Snelling posted a 6.01 ERA and a 5.50 FIP in 73 innings with the Padres’ Double-A affiliate before being traded to Miami for Tanner Scott. He did make improvements over the final two months of the season with Miami.

What Snelling has shown in 2025 looks back to the level of arm talent we saw in 2023, when he was named Baseball America’s Minor League Pitcher of the Year. His ERA is down to 3.06 on the year and is backed by a 2.75 xFIP and 2.94 FIP. The command has steadily improved, and Snelling is rocking a 22.6 percent strikeout minus walk rate.

The fastball used to sit in the low 90s with 16 inches of IVB from a 5’8” release height. Now, it is up to 95 mph on average with over 17 inches of IVB on average. Snelling gets 7-10 inches of arm-side movement with high spin rates for a four-seam and has shown the ability to miss bats.

His slider has some “slurvey” traits, having good depth and sweeping action. It's not quite a curveball, sitting in the low 80s, but it has a -5-inch IVB with 8-10 inches of horizontal. He is comfortable throwing it both in and out of the zone, getting whiffs and chasing. It runs away from left-handed hitters, but Snelling will also throw it to right-handers back foot on occasion.

The changeup has played quite well, generating 14 inches of fade on average while working around 88 mph. The added fastball velocity allows the changeup to play better now, given the separation between the pitches.

With a strike rate of 66.5 percent and a walk rate below 6.6 percent, Snelling looks the part of a high-end pitching prospect again. He should get a shot to pitch with the Marlins over the next few weeks.

Miguel Mendez, RHP, San Diego Padres, 23, AA

After seeing Mendez be a weapon out of the bullpen in the Arizona Fall League, he is now dominating in a starter's role and finally picking up steam in the prospect world. Promoted to Double-A, Mendez made his first start and dominated, striking out 11 batters across six innings of one-hit ball. He has now gone five straight starts without allowing an earned run, and the last time he allowed more than one earned run was May 23.

Mendez is skinny with a lot of projection in his frame, but ultimately, he's taken that leap forward already with the fastball. The primary reason he needs that weight is to maintain velocity in starts.

The fastball reaches 100 mph at times, but has worked closer to 96 mph, which is still plenty of velocity. The pitch plays up thanks to heavy extension and strong traits. Getting 17-18 inches of IVB and over 12 inches of horizontal movement, Mendez spins the pitch exceptionally well.

The slider is a weapon, having late glove-side movement as Mendez spins it exceptionally well. It has carry to it and works in the upper-80s, but it is the late movement profile that lets it miss so many bats. He is comfortably throwing it to both lefties and righties and missing bats. The changeup still needs refinement, but the fastball/slider combo will play.

What looked like a bullpen piece has blossomed into one of the better starters in the minors, averaging six innings per outing over his last six games.

Trey Gibson, RHP, Baltimore Orioles, 23, AA

I have seen enough; I am ready to deem Trey Gibson a top 100 prospect. The dominant season continued on Thursday as he punched out nine batters across six scoreless innings. Gibson allowed five hits, but did not issue a walk while showing his dominance. At this point, it is time for him to move to Triple-A.

Across 52.1 Double-A innings, Gibson owns a 1.55 ERA and a 0.90 WHIP. The strikeout rate is up to 32.5 percent there and 36 percent on the year, while Gibson has walked just 8.5 percent of batters faced.

Having a five-pitch mix, Gibson leads with a fastball that he throws around 40 percent of the time. It grades out at a plus offering, sitting 94 mph with strong characteristics. The pitch plays up thanks to over seven feet of extension and nearly 18 inches of IVB on average.

The slider is around 86 mph with strong sweeping action, while his 80 mph curveball has nice depth. Gibson used a cutter around 15 percent of the time, sitting 90 mph with carry and short horizontal movement. The changeup is Gibson’s least-used offering, mostly against left-handed bats. It is around 90 mph and could almost be classified as a sinker, which I think some do classify it that way. The cutter sits in the upper-80s and has been a good out pitch.

Gibson is legit. I am fully buying in!

David Shields, LHP, Kansas City Royals, 18, A

Shields made his full-season debut after just one pro start at the complex and has dominated since. Thursday marked four straight starts without allowing a run as he struck out eight batters and just one hit across five scoreless innings. For the third straight start, Shields has not issued a walk.

Getting 15 called strikes and 16 whiffs, Shields also landed 66 percent of his pitches for strikes. A good athlete and mover on the mound, Shields has a solid arsenal of pitches with plenty of projection left on his frame. He throws a bit of cross-body, which helps create deception, and he throws from a low slot from the left side.

The fastball sits in the low 90s, but he did tick up during fall instructs. During his senior season, he lived more in the 88-90 range and topped around 91-92 mph. Shields is now topping out closer to 94 mph while working 90-92 mph regularly. The fastball gets solid arm-side movement and can create good riding action up in the zone from his slot.

A slider is Shields’ most secondary pitch, sitting in the low-80s. It has nice depth and long horizontal movement, and Shields has shown the ability to get whiffs against lefties and righties with the pitch. He did a great job locating it on the inner and outer halves of the plate last night.

The changeup is a third offering, but as it continues to develop, it could become a solid platoon-neutralizing pitch against right-handed batters. It sits in the 79-82 mph range with good fading action.

Shields will be a longer development process given that he will be 18 years old for nearly the entire season, but it is a fun arm to dream on. The results speak for themselves as Shields has a 2.18 ERA and a 0.94 WHIP while having a 25 percent strikeout minus walk rate.

Griff McGarry, RHP, Philadelphia Phillies, 26, AA

McGarry has long been known as an electric arm that has trouble throwing strikes. Thursday was one of McGarry’s better days as he punched out 11 batters and did not issue a walk. He needed just 66 pitches to complete five innings of work and landed 70 percent of the pitches for strikes.

McGarry mixes a slider and a cutter, and his four-seam fastball averaged around 95 mph. The fastball does have good characteristics, having high IVB and horizontal movement.

While the walks are inconsistent start to start, McGarry gives vibes of a reliever. But the start, like on Thursday, still gives some hope that McGarry could be something. Across 50.1 innings this year, McGarry has a 4.29 ERA with a 32 percent strikeout rate to a 14 percent walk rate. It is something to keep an eye on moving forward.