But that's not the biggest question. No, more pertinent to Fantasy owners is whether we should care.
He had a chance for his own Jose Berrios moment earlier this week, erasing the bitter memories of his debut last year with numbers more befitting a prospect of his stature, but instead, he had the sort of relief appearance that made it all too easy to send him back to the minors the same day he arrived.
It doesn't mean much on its own, of course, and I'd be remiss if I didn't point out that the 24-year-old has thrown all of 19 2/3 innings in the majors. Less talented pitchers have overcome much worse starts to their careers, and so to dismiss De Leon as a prospect is out-and-out lunacy.
But he isn't the most straightforward prospect. Opinions are split on what kind of pitcher he's supposed to be. While he remains one of the minors' elite bat-missers, averaging 11.6 strikeouts per nine innings in 16 starts last year and 12.1 for his career, the velocity jump that first put him on the map two years ago hasn't held up, and so some evaluators question if his stuff will play the same way against major-league hitters. The results so far, limited though they may be, would seem to support that idea.
But maybe like Luis Severino, De Leon just needs a little fine-tuning. That's the more reasonable approach to take in a long-term keeper scenario. But I think in redraft leagues, we can stop reacting to every promotion and wait until he actually accomplishes something.
So no, De Leon isn't one of my top five prospects to stash, and he may not be asked to start anyway. With a bunch of off days coming up, the Rays can go four-man until Matt Andriese is back from his groin injury. And the next time they have an opening, they may opt to try out Jacob Faria, who has himself emerged as an elite bat-misser this year, or Brent Honeywell, the best of all their pitcher prospects, instead.
Five on the verge
(These are the prospects most worth stashing in redraft leagues.)
Yoan Moncada, 3B, White Sox
2016 minors: .294 BA (405 AB), 15 HR, 45 SB, .918 OPS, 72 BB, 124 K
2017 minors: .312 BA (157 AB), 6 HR, 10 SB, .885 OPS, 24 BB, 50 K
The best prospect in baseball is 3 for 18 since returning from a brief DL stint for a minor thumb injury, but he has shrunk his strikeout-to-walk ratio during that time. Now 22, he has probably done enough to earn a promotion already, which would mean the White Sox are just waiting for some magical date in June when they're comfortable Super 2 won't become an issue down the road (and we could all live with that -- it's June now, after all). But an ill-timed slump could force the White Sox to pump the brakes and extend this waiting game into the second half.
Amed Rosario, SS, Mets
2016 minors: .324 BA (479 AB), 5 HR, 19 SB, .833 OPS, 40 BB, 87 K
2017 minors: .357 BA (210 AB), 5 HR, 11 SB, .914 OPS, 13 BB, 34 K
It's not as clear what the Mets are waiting for -- maybe for Asdrubal Cabrera to do more of what he did Tuesday, nearly costing the Mets a game on a dropped pop-up -- but Rosario continues to do all he can to force the issue, riding a 17-game hit streak in which he has batted .364 (28 for 77) with three homers, four doubles, two triples and four stolen bases. You'd like to see a higher home run total, particularly in a hitter-friendly league, but it's clear from all the extra-base hits that he's no slap hitter. I think there's a Francisco Lindor-like ceiling here.
Rhys Hoskins, 1B, Phillies
2016 minors: .281 BA (498 AB), 38 HR, 116 RBI, .943 OPS, 71 BB, 125 K
2017 minors: .316 BA (177 AB), 13 HR, 41 RBI, 1.050 OPS, 28 BB, 34 K
Hoskins' last two weeks haven't brought him any closer the majors. He has fallen into what might qualify as a slump by his standards, batting .233 (10 for 43) in 12 games. But he has many walks (seven) as strikeouts (eight) during that stretch for a .353 on-base percentage, so his competence certainly isn't in question. I'd feel better about stashing him if either he or Tommy Joseph was seeing action elsewhere on the diamond, but seeing as Hoskins is already 24 years old, something will give here sooner than later. There isn't a minor-leaguer this year whose production has excited me more.
Gleyber Torres, SS, Yankees
2016 minors: .270 BA (478 AB), 11 HR, 21 SB, .775 OPS, 58 BB, 110 K
2017 minors: .260 BA (150 AB), 5 HR, 7 SB, .812 OPS, 23 BB, 30 K
A report surfaced Thursday morning that generated some buzz around the baseball world but really just confirmed what we already suspected: The Yankees would like to replace Chase Headley with Torres if the 20-year-old proves major league-ready over the next couple months. OK, cool. Like that wasn't already evident from the reps Headley was getting at first base. It's not like the timeline is any clearer either since it's contingent on Torres proving he's ready, which so far he hasn't, batting just .207 (6 for 29) in nine games at Triple-A. But it's hard to see me dropping a prospect of this caliber off this list when he's getting this much buzz.
Chris Shaw, 1B, Giants
2016 minors: .267 BA (502 AB), 21 HR, 38 2B, .819 OPS, 48 BB, 125 K
2017 minors: .299 BA (157 AB), 7 HR, 14 2B, .900 OPS, 19 BB, 30 K
You may have noticed the Giants are bad at hitting, ranking second-to-last in runs scored, and first base certainly isn't the reason why. No, it's that gaping hole in left field. So the fact that Shaw, a 2015 first-rounder, has played only left field since his promotion to Triple-A Sacramento a week ago is telling. He's a natural first baseman, after all, so the Giants are clearly putting him on the path of least resistance. They're fast-tracking him, in other words. Because he bats left-handed, there's no telling how he'll fare at AT&T Park once he gets there, but we're close enough to finding out that deep-leaguers may want to scoop him up.
Five on the periphery
(These are some other prospects doing something of note.)
Chance Adams, SP, Yankees
2016 minors: 13-1, 2.33 ERA, 0.90 WHIP, 127 1/3 IP, 39 BB, 144 K
2017 minors: 7-1, 1.24 ERA, 0.97 WHIP, 58 IP, 22 BB, 59 K
I mean, the numbers kind of speak for themselves, right? Having converted from a relief role just last year, Adams hasn't gotten much love from the prospect hounds yet, but his production has only improved every step up the ladder. He has actually cut down on his walk rate with his promotion to Triple-A, compiling a 1.57 ERA in four starts. There do seem to be some concerns about durability and pitch variety given his recent introduction to the role, but he just struck out 12 of the 20 batters he faced in six one-hit innings Wednesday and is quickly emerging as next in line for the Yankees.
Ronald Acuna, OF, Braves
2016 minors: .312 BA (154 AB), 4 HR, 14 SB, .821 OPS, 19 BB, 29 K
2017 minors: .340 BA (197 AB), 6 HR, 26 SB, .935 OPS, 17 BB, 61 K
Having missed much of 2016 with a thumb injury, Acuna was a leap-of-faith type prospect coming into the year, his ranking varying greatly from publication to publication, but so far the 19-year-old has rewarded the leap. Despite the lost development time and despite being one of the youngest players at the level, he has dominated Double-A to the tune of a .415 batting average and 1.102 OPS in 21 games. The strikeout-to-walk ratio is a little disconcerting, but it's not like he doesn't know what he's doing up there.
"He's got a very advanced approach at the plate for a 19-year-old. He keeps it simple," Double-A Mississippi hitting coach Ivan Cruz told MLB.com. "One thing that jumps out at me is his pitch recognition at such an early age. He's swinging at strikes and he's not missing them."
Clearly, Triple-A is already in Acuna's sights, and the way he's hitting now, it's not crazy to think he could get a major-league look this year. Fast riser, this one.
Kyle Tucker, OF, Astros
2016 minors: .285 BA (432 AB), 9 HR, 32 SB, .798 OPS, 50 BB, 81 K
2017 minors: .292 BA (185 AB), 10 HR, 13 SB, .946 OPS, 24 BB, 48 K
The fifth overall pick in the 2015 draft has also made quick work of the lower levels, graduating to Double-A Corpus Christi earlier this week after just 64 games (48 this year) at high Class A. The boost in power this year is particularly encouraging since the Astros' high-A affiliate is no longer in the hitter-friendly California League. It's pure growth, baby, and power was always to be expected for the 20-year-old with the athletic 6-foot-4 frame. Tucker is a dynamic talent and remains one of the most prized prospects in long-term keeper leagues.
Derek Fisher, OF, Astros
2016 minors: .255 BA (478 AB), 21 HR, 28 SB, .815 OPS, 83 BB, 154 K
2017 minors: .335 BA (132 AB), 13 HR, 9 SB, .996 OPS, 18 BB, 46 K
Fisher put up modest numbers in a more neutral environment last year, which is why his explosion in the hitter-friendly Pacific Coast League is deserving of skepticism. Then again, he's also a leading voice in the #FlyBallRevolution.
"In spring training, I started working a lot on my swing and trying to hit the ball in the air a little bit more," he told MLB.com. "That's something that a lot of people are starting to hear more of these days."
He seems to be getting more comfortable with it, too, having homered in three straight games and 11 times in his last 35. The Astros aren't exactly hurting for offense, but at 23, Fisher's day isn't far off.
Ryan Mountcastle, SS, Orioles
2016 minors: .281 BA (455 AB), 10 HR, 28 2B, .745 OPS, 25 BB, 95 K
2017 minors: .330 BA (200 AB), 11 HR, 16 2B, .943 OPS, 7 BB, 37 K
Power was thought to be one of Mountcastle's better tools when the Orioles selected him 36th overall in 2015, but it has come on quickly this year, punctuated by a three-homer game Monday. The walk rate is uninspiring, but considering he's a shortstop who only recently turned 20, that's nitpicking at this stage of his development. This breakthrough has elevated him from being an also-ran among prospects to a genuine asset in dynasty leagues, so check to see if he's still available in yours.