It’s been a big week in the prospect world, with Baseball America and Keith Law both releasing their lists of the top 100 MLB prospects. The Yankees have fared well in both rankings, with six on BA’s and five on ESPN’s, but one pitcher appearing on the former and excluded from the latter.

Chance Adams was ranked 81st on the Baseball America list and was left off of Law’s. The 23-year old is coming off a season in the high minors, posting a 2.89 ERA and 3.76 FIP in the highest level of minor league ball. After parts of three seasons in the Yankees organization, Adams seems poised to make his major-league debut at some point in the 2018 campaign, with many people believing he’s destined for a spot in the rotation.

Sadly, I don’t consider myself part of that group. Adams has some talent, and I think he’ll see time in the big leagues in 2018, but his repertoire and history suggest a bullpen role over a starting spot.

Chance was one of the few pitchers drafted out of college as a reliever before being converted to a starter. The appeal of this is obvious; starters are more valuable than relievers because of their increased workload, and so you’re willing to accept less-spectacular results in exchange for throwing three times as many innings. Adams has been able to do that, to a point, but it’s probably not sustainable for an entire big league career.

There’s no one reason why I’m bearish on Adams’ starting potential, but like a lot of things, it’s a series of smaller reasons. First is simply his arsenal. The biggest difference between starters and relievers is starting pitchers tend to have at least three pitches, and usually more. Pitchers who do rely on three pitches must compensate by having one of those three pitches be near-perfect, or else they become far too predictable facing the best hitters on the planet.

Luis Severino is an example of that type of three pitch pitcher, who sports arguably the best four-seam fastball in the game today. His ability to vary speed, hit his spot and maintain the pitch’s effectiveness compensates for his merely adequate third pitch, the changeup. Contrast that to a pitcher like Jordan Montgomery, who makes up for a less-than-perfect fastball by throwing five pitches from nearly identical arm slots.

Chance doesn’t really have either of those gifts. Both his fastball and slider are good enough, but not really enough to compensate for a lack of a reliable third pitch. That lack of a reliable third pitch is also a serious roadblock to developing four or five pitches like Montgomery throws. Adams, despite his talent, probably just doesn’t have the repertoire to reliably navigate a lineup multiple times.

Let’s return to Montgomery for a minute. Like Adams, Gumby forced himself onto the Yankees radar by pitching so well the front office had to pay attention. Montgomery looks to be secure in the starting rotation for the near future, but clues in his minor league performance show key differences between him and Adams.

To start, Monty consistently increased his strikeout rate in the minors, with his K/9 steadily climbing as he progressed through Low-A to Trenton. At the same time, his walk rate declined the same way, as he gradually faced older and better competition, he issued fewer free passes, down to 2.19 in his final full season in the minors.

Adams is the opposite. His strikeout numbers have dropped while his walk rate has climbed. Even more concerning, his groundball rate has also dropped from 46.1% in 2016 to just 40% this past season. Adams is increasingly relying on outs from fly balls to work through an order, and that’s just not a sustainable strategy when you start 30 games a year.

The best path forward for the Yankees is to focus Adams on working two or three innings at a time. This allows him to go “all out” with his fastball, as he doesn’t have to save energy for a sixth or seventh inning. You’d probably see a bump in his strikeouts closer to his Low and High-A levels, and limit the number of fly ball opportunities he has.

I don’t want to be seen as someone who’s brushing off Chance Adams completely. He has a lot of natural talent, and we’ve seen the impact a reliever can have when he can pitch two innings at a time. David Robertson, Chad Green and Andrew Miller have all been able to work five, six or seven outs for the Yankees in the past few seasons, and their value has been undisputed. Chance Adams is still probably going to be a major league talent, he’ll just likely be working at the end of a game instead of the beginning.