Two Under-the-Radar Non-Roster Invitees to Watch in Cubs Camp

[Matthew Trueblood]

As the first day of camp reminded us, the Cubs' depth of good pitching options will need to be better than it was in 2024, if they hope to make good on projections that they'll win the NL Central this season. In light of that, keep an eye on these two arms with invites to big-league camp.

Image courtesy of © Allan Henry-Imagn Images

It's not like Antonio Santos will be asked to fill in for Javier Assad. It's not even clear that Assad would make the Opening Day roster, should his oblique muscle injury turn out to be mild and he be ready when the season begins next month. If he did have to be replaced, it would be by Colin Rea, Jordan Wicks, Keegan Thompson, or Ben Brown, depending on the health of any of those hurlers and the role you envisioned Assad holding. Eventually, though, if a few injuries or poor performances pile up, the team could find themselves turning to a player like Santos. If Alex Bregman signs elsewhere and the front office pivots to a trade for Dylan Cease that diminishes their strong pitching depth, Santos could certainly slide up the depth chart.

Who is Santos? Well, back in June, the 28-year-old Dominican Republic native signed with the Cubs, out of the Mexican League. He had drifted to that circuit after reaching MLB with the Rockies in 2020 and 2021, then spending 2022 in the Mets system. A fixture in the Dominican Winter League, he nonetheless looked lightyears away from a return to the majors in the States—but now, that seems much more plausible.

Santos pitched 14 times and racked up 70 innings for the Double-A Tennessee Smokies, with a 3.99 ERA and 80 strikeouts against 20 walks. He then went back to the Dominican this winter, but his numbers there were dreadful, with an ERA over 6.00. He's had a long professional journey already, and merely getting an invite to MLB camp is a win for him. By no means is he in line to pitch for the Cubs in the bigs this year, barring something unforeseen, but he's back in that arena, anyway.

How he's gotten there is fascinating. Over time, he's changed his position on the mound and how he tries to disguise his release points, maximizing the utility of each of his pitches.

We have 2024 data thanks to the Dominican Winter League, by the way. While only Triple-A and some Low-A affiliates of MLB teams allow their Statcast data to be shared publicly, some parks in LIDOM have tech, too, and it's easier to get it. As you can see, one adjustment Santos has made is to compress the spread of his release points. He's also working from more of a three-quarter slot; you can see that in the orientation of his distribution in release points by pitch type.

With those changes have come a few alterations in his pitch mix, too. Santos has a mid-90s fastball that he has always supplemented with a changeup and a slider. This year, he added a cutter to that collection, letting the changeup and the slider lose some velocity to increase the separation between the fastball and those offerings. The cutter is a firmer pitch, sometimes pushing toward 90 miles per hour.

Having four pitches he can trust (and a different four than he had in 2021) has given Santos a new lease on his professional pitching life, but so have some tweaks to how those pitches move.

As was true above, the light blue lines here capture his 2024 data; 2023 is in red; and 2021 is in purple. Each point on the shapes I've drawn is the average movement coordinate of one of his pitches. Starting in the top left corner, note that Santos's fastball has more rising action than in the past; that his changeup (lower left) has more depth than ever; and that he has two comparatively close but distinct breaking-ball looks (the slider, lower right; and the cutter, upper right). This arsenal is the best setup to attack left-handed batters Santos has ever had. The difference in movement and velocity between the fastball and the changeup is larger than ever, and the release point differential has only shrunk. His cutter and slider are the kinds of pitches that neutralize opposite-handed batters relatively well.

That's why lefties batted .156/.252/.271 against Santos in 2024. Righties hit him harder, though, and remember, that was in Double A. To have any kind of impact in the majors, he will need excellent command of the stuff he has, or a good way to steer that slider a bit more to the glove side, perhaps using seam-shifted wake. That's not overwhelmingly likely. However, Santos was a solid summer signing, and he's a better 20th pitcher in line than most teams can boast.

Meanwhile, the Cubs also have an intriguing left-handed hurler coming to big-league camp, although he's solely a reliever. Riley Martin, a sixth-round pick from 2021 who turns 27 years old next month, is a tantalizing lefty arm. Over the last two seasons, much of which he spent at Triple-A Iowa, he's fanned 34.1% of opposing hitters. He has a fastball that can touch 95, with good carry, and throws both a slider and a curveball with big movement and big whiff rates. That's the good news.

The bad news is just what you'd expect: Martin walks too many batters. He's given free passes to over 16% of opponents over the same two-year span, plunked four hitters and thrown 12 wild pitches. He has to clean that up in order to have a meaningful shot at surviving in the big leagues, even if the strike zone in MLB has a chance to be slightly more friendly than that in the International League, governed by computers.

With Caleb Thielbar, Luke Little, and Brandon Hughes ahead of him in line for left-handed relief innings and Wicks theoretically available for that role if not needed as a starter, Martin has an even longer path to playing time for the Cubs than does Santos. However, both hurlers bear watching in the Cactus League, because there are always unexpected needs on a pitching staff during a long season, and a bit of positive development by either of these two could unlock something valuable in the event of such an emergency.

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[Development DL]

Am I a nerd , because I love the detail in the analysis of these off the grid,  NRI dudes .