We’ve devoted full articles to the most promising prospects promoted to the majors late this season, but we’ll be offering scouting and fantasy takes on the best of the rest in a two-part series running today and tomorrow. First up: the pitchers, with position players to follow on Friday.

Brian Flynn, LHP, Marlins
Scouting Take:
Flynn, a former seventh-round draft pick (2011) out of Wichita State, was one of the pieces the Marlins acquired at last season’s trade deadline in the Anibal Sanchez/Omar Infante trade, and is the last of the trio to make it to the majors (following Rob Brantly and Jacob Turner). The 6’8”, 240-pound left-hander has seen his strikeout rates spike this season, precipitating a rise through the Marlins system that saw him start the season in Double-A Jacksonville and end it at Marlins Park pitching in front of a similar-sized crowd. He has good control for a tall pitcher and features a low-90s fastball with a good downward plane to go with a pair of usable off-speed pitches—a slider and changeup—and a show-me curveball. The improvement in his changeup is what helped him jump from striking out 7.0 batters per nine innings in 2012 to 8.2 in the 2013 season, and it gives him a chance to stick as a back-end starter. He should compete with Henderson Alvarez, Tom Koehler, and others for a spot in the back of the Marlins rotation next season. —Jeff Moore

Fantasy Take: If you can look past Flynn’s four-inning, three-earned-run, three-homer, more-walks-than-strikeouts flop of a debut, I suggest you do so. If you can’t? I guess I won’t blame you, but you’ll be missing out. Flynn generated a 21 percent strikeout rate in 138 Triple-A innings against a seven percent walk rate. His brief stint in Double-A was even better, with the numbers coming in at 29 percent and 3.5 percent, respectively. The left-handed Flynn attacks hitters with a fastball that can touch the mid-90s and has crude, if developing secondaries. He’s probably not more than a back-of-the-rotation starter, but pitching in the Marlins’ spacious ballpark for a team that will be good sooner than people think, he’s a solid depth option if your minor league system is bare. He’s a deep league add only. —Craig Goldstein


Heath Hembree, RHP, Giants
Scouting Take:
Often billed as a potential closer, Hembree more likely profiles in a middle relief or setup role, with one scout calling his stuff “good for the seventh inning, average for setup.” The 24-year-old righty, who was a fifth-round selection in 2010, dominated his way through the lower minors but has scuffled at times in two Triple-A seasons. Hembree has thrown more strikes this year, attacking hitters with a late-inning mentality while showing a 60-grade (plus) fastball and an average mid-to-upper 80s cut-slider. While he showed 95-96 mph velocity with more consistency in past years, he has sat more in the 92-94 mph range this season with good life. The Giants are working Hembree into their bullpen this month, and a competent showing should put him in position to crack the club’s opening-day roster next spring. —Jason Cole

Fantasy Take: Long hailed as the “closer of the future” for the Giants (a precursor to Proven Closer), Hembree is making his MLB debut a bit later than many expected. The right-hander put up a decent season in Triple-A, notching 63 strikeouts in 55 1/3 innings and lowering his BB/9 to 2.6. With Sergio Romo safely entrenched as San Francisco’s closer, I wouldn’t expect Hembree to be of particular fantasy worth in non-holds leagues next year, but bullpens rarely shake out the way we think they will. Hembree’s a nice grab in very deep leagues now if you need strikeouts, and even if he doesn’t quite fit the profile, he should be on everyone’s closer watch list assuming he breaks camp with the Giants in 2014. —Ben Carsley


Erik Johnson, RHP, White Sox
A teammate of fellow White Sox September call-up Marcus Semien at Cal, Johnson should have an opportunity to lock down a full-time rotation spot in Chicago this month and early next season. The 23-year-old righty is perhaps the organization’s top pitching prospect, and while he doesn’t have a sexy profile, it’s plenty valuable to a big-league club. Johnson’s strike-throwing ability with solid-average stuff and 6’3”, 235-pound frame should enable durability at the back of a rotation, likely as a no. 4 starter. He’ll generally pound the zone with a four-pitch mix that includes two 60-grade (plus) offerings in his low-90s fastball (touching mid-90s) and upper-80s slider. Johnson also mixes in an average curveball and fringy changeup. The White Sox have seen Johnson struggle with his command in two big-league starts thus far, but expect it to improve as he settles into the level. —Jason Cole

Fantasy Take: Fantasy owners might be familiar with Johnson, who was mentioned in The Sporer Report preview of September call-ups and who hasn’t posted an ERA higher than 2.74 at any level since a 2011 stint in rookie ball. He’s thrown 9 2/3 innings in the big leagues so far, and while I wouldn’t expect him to be of any use in 2013, as a 2014 stash (if you have a minor league), I like him. (I placed a waiver claim on him in my own league, but it wasn’t high enough.) He could be a solid fourth fantasy starter in due time, but he’ll need some room to open up in the White Sox rotation first. —Craig Goldstein


Jimmy Nelson, RHP, Brewers
Scouting Take:
Most often pegged as a future late-inning reliever entering this season, Nelson has a few more scouts believing he can stick in a starting rotation following his solid performance between Double-A Huntsville and Triple-A Nashville. The 6’5”, 245-pound righty certainly has the body to handle a big workload, and he features a lively low-to-mid 90s fastball and solid-average slider. While his changeup has improved, it’s still on the fringy side, and his funky delivery leads to questions about his ultimate command profile. Nelson’s command has shown better in bursts this season—though it was once again inconsistent in Triple-A—and the safer bet is probably late-inning relief over no. 3 or 4 starter. Regardless of the right-hander’s role, he’s a big-league-caliber power arm and should make an impact in Milwaukee next season. —Jason Cole

Fantasy Take: Nelson is projected to pitch out of the bullpen for the remainder of 2013, and in that role he has little fantasy value. However, those looking toward 2014 should at least flag the big right-hander, as his ability to keep the ball on the ground and strike batters out might make him a mid-rotation starter some day. That “might” is largely predicated on Nelson’s command, which was great in Double-A and then not so great in Triple-A this season. Nelson doesn’t have a huge ceiling, and I don’t expect him to be handed a job in the major-league rotation out of spring training. He should see some MLB starts at some point in 2014, though, and that’s when NL-only owners desperate for Ks should go Full Nel … no, I won’t do that to you. That’s when NL-only owners should pick him up. —Ben Carsley


James Paxton, LHP, Mariners
Scouting Take:
With Taijuan Walker and Paxton both earning call-ups this month, two of Seattle’s vaunted “big three” arms have now reached the major leagues. Left-hander Danny Hultzen appeared on track to do so as well after a strong early-season performance, but he has been shut down with shoulder issues for much of the campaign. He’ll pitch in the Arizona Fall League, and all three could be in Seattle at some point next season.

Paxton is the least likely of the trio to make an impact at the top or middle of a big-league rotation—I recently wrote him up as an arm-strength middle reliever—but he does have upside. A long-limbed 6’4” southpaw, Paxton can produce serious downhill plane on his big fastball, which worked anywhere between 88-96 mph (sitting 92-94) when I saw him last month in Triple-A. His velocity ticked up in his MLB debut last week, as the pitch averaged just a shade over 95 mph. He’ll also mix in a curveball that flashes plus, a promising cutter, and an occasional below-average changeup.

Paxton’s long arms and overall issues in his delivery have caused inconsistent command and results this season. While that may always be the case with him, it’s possible that he’ll improve enough to stick at the back end of a rotation or work into a setup relief role. The Mariners will likely enter this offseason with three 2014 rotation spots up for grabs, and Paxton is beginning his audition for one of them this month. —Jason Cole

Fantasy Take: Probably the most notable prospect on this list, Paxton made his MLB debut on Saturday and tossed six innings of two-run ball against the struggling Rays in Safeco Field. Said scenario represents when fantasy owners would be wise to play Paxton for the rest of the season: when he’s at home and facing a bad or slumping offense. The only real exception to this rule would come if you have a big cushion in WHIP and are desperate for strikeouts. But be forewarned that while gambling on Paxton comes with some upside, he’s also capable of walking the world and giving up runs in batches. He’s a candidate for spot starting in the majority of mixed leagues, but don’t fall in love with him just because of name value. —Ben Carsley

Thank you for reading

This is a free article. If you enjoyed it, consider subscribing to Baseball Prospectus. Subscriptions support ongoing public baseball research and analysis in an increasingly proprietary environment.

Subscribe now
You need to be logged in to comment. Login or Subscribe