Modesto, California —— The Modesto Nuts currently possess the best record in the California League—and they won the circuit’s North Division First Half crown—in large part because of a strong pitching staff. Mmre specifically, an exceptional core group or power relievers is flashing mid 90s and often turning games into six-inning affairs when right. Through large portions of 2017, the combination of Art Warren, Matthew Festa, Lukas Schiraldi, Spencer Herrmann, Matt Walker, Joe Pistorese, and Bryan Bonnell have guided the Seattle Mariners‘ High-A affiliate to a successful summer while flashing projectable talent beyond just this High-A hitter’s circuit.
Here are the seven big Seattle Mariners relief arms you should be following in Modesto, with video(s) of each pitcher. If you like the videos, go help yourself to some more: please click here and subscribe to our YouTube channel. (Also, all listed stats are up to date entering play on Monday, July 3.)
Art Warren, RHP
2017 Stats: 2-1, 2 SV, 3.89 ERA, 23 G, 34.2 IP, 35 H, 16 BB, 32 K, .271 opp. BA
We’ve discussed Art Warren at length before; back in May, I broke down all the things that had changed this year for the the Seattle Mariners’ former 23rd round pick. And then in June, Warren spoke to us about his commitment to offseason training and subsequent bump in velocity. Right now, to put it bluntly, he’s throwing the hell out of the ball. He’ll sit 91-94 mph with his fastball, topping out at 95 mph. He couples that with a 75-76 mph curveball and a distinct 81-84 mph slider.
A former starter, Warren has the stamina to work multiple innings, the deep repertoire to see a lineup multiple times, and the velocity and raw stuff to work late in games. I expect the Seattle Mariners to promote him to Double-A at some point in the second half, but for now, he’s completely reinvented himself as a power arm out of the bullpen and he looks damn good doing it.
Matthew Festa, RHP
2017 Stats: 3-2, 2 SV, 3.43 ERA, 23 G (1 GS), 44.2 IP, 37 H, 12 BB, 60 K, .220 opp. BA
If Art Warren is the wonderful breakout story, Matthew Festa is the steady, quiet, lights-out power arm anchoring the late innings in Modesto. The Seattle Mariners plucked Festa out of East Stroudsburg University in the seventh round last June, and this summer he earned his way into the Cal League All-Star Game thanks to exceptional short relief work. Festa sits from 90-94 mph with his fastball, topping out at 96 mph. Like Warren, Festa pairs it with three off-speed pitches: a curveball (77-80 mph), a true power slider (84-88 mph), and a changeup (82-84 mph).
Consistent mechanics and clean arm action suggest Festa is a pretty polished pitcher relative to his level of pro experience. He may yet find more velocity as his career continues, but with as deep a repertoire and as strong a command profile as he has, Matthew Festa is quickly becoming an interesting swingman reliever who can throw multiple innings and miss bats all at once. That’s a relatively unique skill set in an age of matchup relievers and short stint specialists, and one that bears watching as he develops.
Lukas Schiraldi, RHP
2017 Stats: 1-0, 2 SV, 4.22 ERA, 24 G, 32.0 IP, 23 H, 23 BB, 55 K, .198 opp. BA
Lukas Schiraldi was brutally bad when I saw him as a starting pitcher last summer with the Bakersfield Blaze. He walked 24 batters over 22 innings across seven games (five starts) in Bakersfield, throwing to the tune of an 0-3 record and a 7.77 ERA in his brief stay there. His mechanics were completely out of whack, his fastball underwhelming and flat over the hittable parts of the plate, and his slider inconsistent to the point where it became difficult to trust in most any situation.
I mention all this not to bring up bad memories, but to give a little bit of context for the exceptional player development the Seattle Mariners and Lukas Schiraldi have undertaken ahead of 2017. A full-time reliever now, Schiraldi is walking too many people and he still has some command issues—with a jerky-jerky motion and arm action, he likely always will—but he has enough feel for the strike zone that he can survive by being effectively wild. Further, a complete overhaul of his breaking ball has made it a legitimate wipeout pitch that’s missing bats far more often than it did last year. Opponents are hitting just .198 against him now, and for good reason: nothing he throws is straight, and though it’ll burn him now and then with too many free passes, he’s starting to channel it well enough to use as a tool. Big and strong with raw arm strength, too, Schiraldi has a future making hitters uncomfortable in pro ball if he can keep throwing just enough strikes to survive through his (effectively) wild ways.
Spencer Herrmann, LHP
2017 Stats: 3-1, 2 SV, 2.16 ERA, 24 G (2 GS), 41.2 IP, 37 H, 11 BB, 41 K, .243 opp. BA
The only lefty who makes this list, Spencer Herrmann is a bit like Schiraldi in that Herrmann, too, went from an underwhelming stint in Bakersfield last year to a key cog back in Modesto for 2017. Good size and good deception in arm action are among Herrmann’s best assets, and he pitches just like you’d expect a 23-year-old college product to pitch at this level: fill up the strike zone with no frills, always attacking hitters from both sides of the plate. Down the line, Herrmann ought to be ticketed for left-handed specialist roles, but for now he’s generally throwing more than one inning at each turn, and that’ll help him build experience in various matchup situations. A big, consistent breaking ball may well be his calling card, though, and Herrmann can be hell on lefties with it sweeping across the strike zone.
Matt Walker, RHP
2017 Stats: 3-1, 4 SV, 3.12 ERA, 23 G, 34.2 IP, 30 H, 15 BB, 32 K, .238 opp. BA
Blessed with less natural velocity than some of his counterparts on this list, Matt Walker makes up for it with a good sense of the strike zone and a lot of deception in his arm action that does well to hide the ball from hitters as long as possible. The product of Weatherford College in Texas sits 88-89 mph with his fastball, and works 80-82 mph with a tight-breaking slider that is more likely to draw weak contact than miss bats at a high rate.
Walker’s arm action is the interesting component here; his natural arm path hides the ball from hitters and likely gives them the impression his fastball is harder than it really is because it can sneak up. In a way, that gives Walker another wrinkle with which to work, and his ability to change speeds and throw off-speed for strikes comes into play in how he’s able to keep hitters off balance and lunging at his stuff. Long term with his velocity, the Seattle Mariners are likely ticketing him for fringy long relief, but for now Matt Walker leads the club in saves and is proving to be nails in tight situations.
Joe Pistorese, LHP
2017 Stats: 0-1, 2.89 ERA, 11 G (1 GS), 18.2 IP, 16 H, 7 BB, 20 K, .225 opp. BA
Perhaps not ideally on the list considering he’s been on the disabled list since May 31, I felt it somewhat important to include Joe Pistorese if only because he’s another lefty like Herrmann with some deception and matchup potential. For Pistorese, that centers on a quirky delivery and herky-jerky arm action that’ll confuse hitters and tie up lefties. He throws a ton of strikes—just 18 walks in 95.1 career professional innings—and that’ll serve him well considering his velocity and stuff are both average. But it’s his deceptive movements and knack for sequencing lefties that’ll take Pistorese however far he’s to go; if Warren and Festa are reliable multiple-inning guys, Pistorese (and Herrmann) make for exceptional counterparts in highly specialized short relief during close games.
Bryan Bonnell, RHP
2017 Stats: 2-4, 6 SV, 4.46 ERA, 24 G (1 GS), 36.1 IP, 41 H, 7 BB, 30 K, .285 opp. BA (includes stats from the Tampa Bay Rays‘ organization)
It’s not just homegrown guys impressing with the Seattle Mariners at High-A this year; righty Bryan Bonnell was acquired from the Rays on May 9, and he’s racked up two wins and two saves in the last two months with Modesto. Another big righty with the stamina for a bit of length in his outings like Warren and Festa, Bonnell sits 93-94 mph and tops out at 95 mph. He’ll couple it with an 86-88 mph changeup, and a 77-82 mph breaking ball that shows good depth and sits in between a true curve and a hard slider, though with enough life that it’s not a middling slurve. His arm strength and unique arm action give Bonnell an advantage in going up the ladder when he needs to, and even though that hasn’t yet manifested itself in big strikeout totals, I think the UNLV product isn’t far from missing a lot of bats. Beyond that, he’s got an outside shot at a seventh-inning type of role with his pitch life and arm strength, assuming his relatively deep repertoire and solid command profile hold up over time.