Padres Prospect Hot Sheet: Kash Mayfield Checking the Domination Box

Checking in on the San Diego Padres prospects who made a mark in the last week:

Kash Mayfield, LHP, High-A Fort Wayne

Season stats: 3-1, 1.52 ERA, 7 games (all starts), 29⅔ IP, 9 H, 5 R, 5 ER, 1 HR, 13 BB, 35 K, 

Just a few months after turning 21 years old, the 2024 first-round draft choice (25th overall) out of Elk City High School in Oklahoma is seeing his star rise in the early stages of 2026. The 6-foot-4, 200-pound left-hander allowed one hit and struck out a career-high nine with no walks over five shutout innings as the Fort Wayne TinCaps beat the Cedar Rapids Kernels 12-3 Friday. He threw just 56 pitches, including 43 strikes. Mayfield hasn't allowed a run in five of his seven starts this year and currently has a 12-inning scoreless streak.

If that sounds like a remarkable performance, it is. The only thing is that Mayfield has three other five-inning, one-hit outings this year, which have contributed to his 1.52 ERA, 0.74 WHIP and 0.99 opponent batting average, all of which lead the Midwest League.

His latest outing earned Mayfield, Padres Mission's No. 2 prospect, the Midwest League Pitcher of the Week award. Against the Kernels, Mayfield retired the first 13 batters of the game and struck out nine of the 16 batters he faced. He also induced 16 swinging strikes. He has a 32.7% strikeout rate and 12.1% walk rate. Of his 13 walks, five came in one game. The MLB averages for both are 22.2% and 8.6%.

Mayfield has also excelled at limiting contact. While his four-seamer velocity is low (91 mph range), his ability to locate the ball, along with an excellent slider and changeup, helps with the strikeout and contact success. In his seven starts, he has allowed three hits twice. In the other five, Mayfield allowed one hit in three and no hits in the other two, with both of those coming in his first two starts of the season.

In his pro debut last year at Low-A Lake Elsinore, Mayfield made 19 starts and had a 2.97 ERA in 60⅔ innings. He had a 34.1% strikeout rate and 10.9% walk rate.

Mayfield's domination, thanks to his ability to pitch and not just throw the ball past hitters, at High-A could lead to a quick promotion to Double-A San Antonio, where he could work with catcher Ethan Salas, Padres Mission's No. 1 prospect. Not that he isn't working with a good catcher currently (see next item).

Lamar King Jr., C, High-A Fort Wayne

Season stats: .278/.399/.400, 34 games, 6 2B, 1 3B, 2 HR, 14 RBI, 20 BB, 29 K, 8 SB, 1 CS

The fourth-round draft pick in 2022 out of Calvert Hall College High School in Maryland has been an on-base machine. The right-handed hitter, son of former Seattle Seahawks defensive end Lamar King, currently has a 27-game on-base streak going, needing an infield single in the ninth inning Saturday to keep that streak alive. Over five games last week against the Kernels, King had three straight multi-hit games and went a combined 7-for-22 with three RBIs.

While King—Padres Mission's No. 10 prospect—only drew one walk last week, he has 10 already in May after having 10 through the entire month of April, which has helped build a very nice .399 on-base percentage. After going 0-for-3 Tuesday, King went 2-for-5 in each of his next three games, scoring a run each game. He hit his first triple of the season Wednesday. His three multi-hit games last week gave him eight for the season. Since April 14, King ranks fifth in the Midwest League with a .341 batting average and 10th with a .434 OBP.

King's pro debut was delayed until late 2024 by shoulder surgery. He played in 62 games between the Arizona Complex League and Low-A Lake Elsinore, putting up a .271/.379/.421 slash line with two homers and 32 RBIs. He spent 84 games back at Lake Elsinore in 2025 and was a bit better offensively, registering a slash line of .286/.370/.408 with four homers, 37 homers and 18 stolen bases. That earned him a promotion to Fort Wayne, where he appeared in 34 games with a .233/.289/.300. He didn't homer and drove in seven with three steals.

That led him to a return to the TinCaps this year and he is thriving. His hit tool has developed quite a bit since being drafted, while the power has yet to follow. King has just two homers this year to go along with six doubles and that triple. He figures to stay at Fort Wayne until at least Salas is promoted to Triple-A, depending on how the Padres see his progress behind the plate. His shoulder injury has some seeing him moving to first base.

Jesus Castro, RHP, Low-A Lake Elsinore

Season stats: 0-1, 3.55 ERA, 6 games (all starts), 25⅓ IP, 26 H, 11 R, 10 ER, 1 HR, 10 BB, 25 K

Just a few weeks shy of turning 19, the right-handed starter turned in his best performance of the season in the Storm's 4-0 shutout of the Rancho Cucamonga Quakes. Castro struck out a career-high nine while going 5⅔ innings for the second consecutive start. His nine strikeouts were two better than his previous game and one more than he had last year in a Dominican Summer League game that was his previous career best.

The younger brother of another Padres pitching prospect, San Antonio Missions right-hander Manuel Castro, hasn't allowed more than three runs in any of his six starts this year and blanked the Quakes despite allowing a season-high seven hits. He also fell an out shy of matching his career high for innings (six), which he did twice last year in the DSL. While he has walked 10, four of those came in a single game. He didn't walk anyone in his previous start.

Castro hasn't popped up on national top-30 lists for the Padres, but could by the end of the year if he continues these types of performances.

Kerrington Cross, 1B-3B, Low-A Lake Elsinore

Season stats: .288/.464/.507, 29 games, 6 2B, 2 3B, 2 HR, 16 RBI, 21 BB, 22 K, 3 SB, 0 CS

Back for a second stint with the Storm after a 14-game cameo in his pro debut a year ago, the 24-year-old was the Padres' seventh-round draft choice in 2025 out of Cincinnati. He has been in the middle of a fun Storm offense and last week went 8-for-17 with three doubles, a homer and eight RBIs. He also drew six walks. His best game against the Quakes was Friday, when he came off the bench and went 2-for-2 with a two-run homer in a 14-0 victory. Cross also had the tie-breaking two-run double in Saturday's 4-2 win.

The Honolulu native posted a .190/.433/.214 slash line in his brief time with Lake Elsinore last year, but that has changed in a big way this time around. He has shown an ability to get on base as he drew 14 walks last year and has 21 in 29 games this year.

He spent all four years in college at Cincinnati, putting up a .396/.526/.647 slash line as a senior with 12 homers, 50 RBIs and 15 steals in 56 games and was named Big 12 Conference Player of the Year. During his career with the Bearcats, he finished third in runs scored and fourth in hits, homers and triples, while winding up fifth in RBIs.

The positional versatility on the infield corners should serve him well, but he will have to continue to hit in order to keep progressing in the system. A move to the outfield, at least to increase his defensive value, isn't out of the question, either.

Victor Lizarraga, RHP, Double-A San Antonio

Season stats: 2-4, 6.37 ERA, 8 games (6 starts), 29⅔ IP, 29 H, 24 R, 21 ER, 3 HR, 20 BB, 24 K

The 22-year-old right-hander was born in San Diego but signed with the Padres in 2021 as an international free agent out of Mexico. He climbed the system to reach Double-A San Antonio as a 20-year-old in 2024, but has stayed with the Missions each of the next two years. His 2026 got off to a rocky start as he allowed seven runs while getting just one out in his second start of the season, then followed that with six runs in 1⅓ innings.

But since then, he has been much better. That includes his start Saturday against the Wichita Wind Surge in which he went six innings, allowing two runs (one earned) on six hits with no walks and a season-high eight strikeouts, just two K's shy of his career high set in 2024 with the Missions. Lizarraga has had an issue with control as shown by his 20 walks (14.8% walk rate) this year and five hit batters while not having big strikeout stuff.

This start followed two appearances out of the bullpen the previous week against the Midland RockHounds in which he pitched a total of eight innings, allowing one run on six hits with three walks and three strikeouts. In his last five games, he has allowed a much-improve .225 opponent batting average (.271 for the season). Perhaps those relief outings against the RockHounds could be a sign of a better role for him down the line if his numbers as a starter don't improve.

Interested in learning more about the San Diego Padres' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!