MLB Pipeline will unveil its 2019 Top 100 Prospects list with a one-hour show on MLB Network and MLB.com on Saturday, Jan. 26, at 8 p.m. ET. Leading up to the release, we look at baseball's top 10 prospects at each position.
Jesus Luzardo cracked last year's list of the Top 10 left-handed pitching prospects at No. 8 even though he had logged fewer than 50 professional innings in his return from Tommy John surgery.
Flash forward a year and the 21-year-old southpaw now headlines our Top 10 LHP list, ranking as one of the top pitching prospects in baseball after a tremendous first full season in which he nearly reached the Major Leagues.

He is one of seven members on our Top 10 who were selected out of the high school ranks, and overall, nine players are products of the Draft. The only non-Draft pick of the group, Adrian Morejon of the Padres, signed for $11 million in July 2016.
Top 10 Prospects by Position
Speaking of the Padres, their organization has four left-handers on this year's list, marking the first time a team has had that many players on a single list in the nine years that we've been putting out Top 10 by Position rankings. Meanwhile, the A's and Rays both check in with two members each.
The Top 10 (ETA)

1. Jesus Luzardo, Athletics (2019)
   
2. MacKenzie Gore, Padres (2021)
   
3. Brendan McKay, Rays (2020)
   
4. A.J. Puk, Athletics (2020)
   
5. Justus Sheffield, Mariners (2019)
   
6. Adrian Morejon, Padres (2020)
   
7. Matthew Liberatore, Rays (2021)
   
8. Logan Allen, Padres (2019)
   
9. DL Hall, Orioles (2021)
   
10. Ryan Weathers, Padres (2021)
    Complete list »
    Top tools
    Best Fastball: Puk (70)
    Puk's fastball was sitting in the mid-90s and frequently hitting 96- to 97-mph before he underwent Tommy John surgery last April. He shouldn't have any trouble producing the same type of velocity with a healthy return to the mound in 2019, though as is the case with many Tommy John recipients, his control of the pitch may initially lag behind.

Best Curveball: Gore, Morejon, Liberatore (60)
Gore's curveball is a plus offering, thought it wasn't as sharp last year in the Midwest League as he dealt with a blister issue. Morejon's deuce, on the other hand, took a step forward last year, and Liberatore showcased his plus curve across two levels last year during his pro debut.

Best Slider: Puk, Sheffield (65)
Puk's slider is one of the best in the Minors, a legitimate swing-and-miss offering that registers in the mid- to upper-80s and is effective against hitters on the both sides of the plate and helped him register 184 strikeouts over 125 frames in 2017. Sheffield's slider is less consistent but earns similar grades and serves as his out-pitch.

Best Changeup: Luzardo, Allen (60)
Luzardo and Allen earn plus grades for their respective changeups, and both lefties use the pitch to neutralize right-handed hitters. Allen held righties to a a .209/.292/.322 line in 2018, and they mustered just .213/.270/.333 against Luzardo.

Best Control: Luzardo, McKay (60)
The two-way McKay demonstrated exceptional control last season as he issued just 1.6 walks-per-nine over 78 1/3 frames in the lower Minors. Luzardo is younger and has more gains to make, but he also should have plus control once he's fully developed.
Highest Ceiling: Luzardo
As a 20-year-old pitching for the first time since Tommy John, Luzardo showed all the ingredients needed to become a frontline starter in the big leagues -- and possibly very soon. He has a premium arsenal in a fastball, curveball and changeup that all grade as above-average or better, as well as control and command that allow him to execute each pitch. If it all comes together for him, Luzardo could be one of the game's best left-handed pitchers and a perennial Cy Young Award candidate.
Highest Floor: McKay
McKay has had considerably more success as a pitcher than a position player as a pro and ostensibly stands to reach the Majors faster in that role. While nothing he throws is truly overpowering, McKay can dissect the zone with precision using his entire arsenal, inducing a healthy mix of whiffs, weak contact and very few walks. Altogether, it gives McKay a safe floor as at least a backend starter at the highest level.

Rookie of the Year Candidate: Luzardo
Luzardo ascended from Class A Advanced Stockton to Triple-A Nashville last season and nearly reached the Major Leagues before the A's shut him down due to workload. It shouldn't be long before he assumes a spot in the A's 2019 rotation, and many within the organization view Luzardo as one of the best pitching prospects in franchise history.
Highest Riser: Hall
The Orioles' first-round pick from 2017 had his workload limited during his first full season, never eclipsing 90 pitches in an outing, but he made big improvements during a dominant second half in the Class A South Atlantic League, posting a 0.84 ERA with 64 strikeouts and a .171 BAA over his final 53 2/3 frames (11 starts).

Humblest Beginnings: Allen
Originally an eighth-round pick -- making him the lowest Draft pick on our list -- by the Red Sox in 2015 before joining San Diego in the Craig Kimbrel trade, Allen faced some injury concerns early in his career but put it all behind him with a breakout 2018 campaign. He projects as a high-probability backend starter, perhaps more with better control.
Most To Prove: Puk
Puk was poised to pitch meaningful innings for the A's in 2018 before Tommy John surgery wiped out his year. He showed huge upside before getting hurt, especially in regards to missing bats, and all eyes will be drawn to the 2016 first-rounder when he returns to the mound this season.
Keep An Eye On: Daniel Lynch, Royals
The Royals had Lynch, the No. 34 overall pick in the 2018 Draft, focus on throwing more four-seam fastballs last summer and saw his heater sit at 92- to 95-mph and touch 97 during his impressive pro debut. That uptick in velocity, along with his feel for three average-or-better secondaries, could put Lynch firmly on the prospect radar in his first full season.