10/29/26 : Annual Phillies Minor League Player Notes - Pitchers - Part Ten
Written by Steve Potter
This Phillies off-season I continue the series “Annual Phillies Minor League Player Notes” with profiles presented in groupings by defensive positions for the players who were still part of the minor league player development program at season’s end. The notes will reflect statistics, my thoughts on each player and input from them and others as I have it. They are presented in order by position and then alphabet in groupings of five players per article. Here is part ten - pitchers, highlighting the following :
Mavis Graves
Tanner Gresham
Daniel Harper
David Hernandez
Sam Highfill
LH Mavis Graves - 22 years old (23 on 11/20/26) - drafted in 6th round of the 2022 draft from Eastside HS, Taylors, SC
2026 Stats : began the year with Jersey Shore making 16 starts (58.1 IP) posting a 4.78 ERA with 86 K’s and 29 walks. Was promoted to Reading on 7/27 - made 14 regular season appearances there (18.2 IP) as a reliever recording a stellar 0.96 ERA with 31 K’s and 14 BB. Did not allow an earned run in his last 13 regular season games (17.2 IP) with a dominating 29 K’s against 10 walks. Made three post season appearances - 3.2 IP - 0 R, 0 H, 4 K’s, 2 BB finishing the year with 16 consecutive appearances without allowing an earned run (two unearned runs) and just 9 hits in 18.1 IP with 33 K’s. Overall 2026 season numbers including playoffs - 80.2 IP, 33 appearances, 3.68 ERA, 121 K’s, 45 BB.
2026 Notes : after being promoted to Reading he transitioned to the bullpen with developmental plans that he would eventually become a one to two inning per outing reliever in the show. Pitching Development Director - Programming Travis Hergert told me that Mavis “spins two breaking balls and gets a ton of whiffs”. Graves features a four seam fastball in the 91 to 94 mph range, slider (cutter), sinker, sweeping curve and a very good change-up. He’s a big fella at 6’6” with a good competitive approach. He delivers a natural lefty screwball like tail on his fastball and big league break on his off speed deliveries. Lefty relievers can make a great deal of money in the big leagues with specialized skills that lead to longevity. After 64 minor league starts over four seasons Mavis has embarked on a new path that hopefully pushes him all the way up the development ladder. He’s off to a great start after playing a key role in Reading’s climb to the Eastern League championship. Rule 5 eligible this off-season.
Mavis’s thoughts on his development during the season :
“ I was really happy with my progression this year, I was a starter halfway through the year and changed to a reliever. Though I was only coming out of the bullpen for almost two months I got to learn some of the roles and how to go about my business in the bullpen. It was definitely different but once I got my routines on track and adjusted I loved it. I still can add a lot of stuff into my prep of being a reliever and I’m excited about that.”
Mavis’s thoughts on the jump to the AA level : “I only played a couple of months in AA but I could tell once I got there that the approaches were much tougher to face and that each batter had something that stood out for them, making it a little bit tougher. Development side I think the short two months even made me a lot better on the mound just trying to read hitters and what they were looking for.”
2027 Outlook : a return to Reading to open the season is likely however with continued success a bump up to Lehigh Valley is very much within reach. Now has a clearer path the big leagues.
RH Tanner Gresham - 25 years old (26 on 9/23/27) - signed as an un-drafted free agent 8/13/24 - United States Military Academy
2026 Stats : began the season with the Clearwater Threshers - 12 appearances (11 starts) recording a 2.95 ERA in 42.2 IP with 51 K’s and 23 walks. Promoted to Jersey Shore on 6/16 - made 12 starts - 56.1 IP, 4.95 ERA, 53 K’s, 28 BB. Finished the year strong - in his last 6 starts - 29.2 IP, 3.64 ERA, 30 K’s, 14 BB. Best month was June - 1.27 ERA in five appearances (four starts) in 21.1 IP with 24 K’s & 11 walks. Overall numbers in his first pro season - 24 appearances (23 starts), 4.09 ERA, 99 IP, 104 K’s, 51 BB, 1.41 WHIP, 9.45 K/9.
2026 Notes : the Phillies signed Tanner after he played four seasons for Army. He had missed most of the 2024 year coming back from offseason Tommy John surgery but returned to action in late April and made five appearances. In 2023 he was the Patriot League Pitcher of the Year and was both a starter and reliever in his collegiate career - he graduated from Hopewell High School in Huntersville, NC. Finished serving his military commitment and was officially activated on 1/19/26 when he participated in Winter High Performance Camp, Minor League Mini Camp and Minor League Spring Training. I was able to watch him in a live BP session on 3/9 - threw strikes and had good pop - word was he had touched 97 mph in camp.
Tanner’s fastball during the season sat in the 92-96 range, he often touched 97. He also threw a slider, sinker, cutter, changeup and curve. On June 3rd those pitches all meshed as he threw five scoreless no hit innings against the St Lucie Mets with 8 strikeouts and 1 walk as part of a three man seven inning no hitter (Marty Gair & Gabe Craig finished it with an inning apiece). He’s got a great attitude and outlook - a winner’s mentality and a skillset that project him climbing the ladder. An under the radar hurler who knows how to attack hitters and has the repertoire to excel.
2027 Outlook : likely opens the year with Jersey Shore but could push in spring camp to bump up a notch to Reading.
RH Daniel Harper - 27 years old (28 on 6/1/27) - drafted in 17th round of the 2022 draft from the University of Kentucky
2026 Stats : split the season between Reading and Lehigh Valley. Was assigned to Reading on 3/25, transferred to Lehigh Valley on 4/14 and transferred back to Reading on 6/2. Made 11 appearances with Lehigh Valley - 6.75 ERA in 10.2 IP, 9 K’s, 7 BB. At Reading made 31 appearances (37.2 IP) posting a 4.54 ERA with 32 K’s and 22 walks. Overall made 42 appearances (48.1 IP) recording a 5.03 ERA with 41 K’s and 33 BB. Made one post-season appearance - a scoreless inning with two strikeouts. Finished the year strong with five scoreless appearances (including playoffs) - 6.2 IP, 7 K’s, 1 BB.
2026 Notes : fastball ranges from 92 to 95 mph - it has touched 98. He was a FB/Cutter/Sinker closer at Kentucky, as a pro he incorporated a couple more pitches including a slider (gyro type) and change up (split finger action). After a stellar 2024 campaign has struggled the past two seasons with command and control - when he’s on is a viable back end of the bullpen asset with big league stuff.
2027 Outlook : with a solid ST camp a return to Lehigh Valley to begin the season is probable.
LH David Hernandez - 19 years old (20 on 5/21/27) - signed as an international free agent 1/15/25 - Culiacan, Mexico
2026 Stats : recorded a 6.23 ERA in 14 appearances (nine starts) in 30.1 IP for the FCL Phillies with 45 K’s and 17 walks. Had a strong month of May (2.70 ERA in 5 games - 10 IP, 19 K’s, 5 BB but battled control and command thereafter.
2026 Notes : spent the entire 2025 season on the IL at the Dominican Academy. Came stateside for his first official game action. Fastball range sits 88-91, slider, change up and curve. Uses pitch ability to get outs.
2027 Outlook : likely returns to FCL for another season.
RH Sam Highfill - 25 years old (26 on 11/30/26) - signed as non drafted free agent 7/29/25 - NC State University
2026 Stats : made 26 appearances (nine starts) posting a 6.57 ERA in 74 IP with 83 K’s and 35 walks for Jersey Shore. Best month was April - 4 appearances (three starts) - 17 IP, 2.65 ERA, .151 BAA, 0.94 WHIP.
2026 Notes : is a reliable innings eater - four seam fastball in the 91-95 mph range, slider, sinker, change-up, curve and cutter. Has a great competitive spirit and knows how to pitch. In the last two seasons he has made 50 appearances with Clearwater and Jersey Shore totaling 180 IP. He’s from Apex, North Carolina - his grandfather, Joel Gibson played baseball at UNCW and NC State, and pitched professionally for the Chicago White Sox and Philadelphia Phillies from 1962-64.
2027 Outlook : should compete in ST for a spot with Reading.
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