Red Sox pitching prospect Hayden Mullins went a career-high 5 2/3 innings in his final outing of the season for High-A Greenville last Wednesday.
Taking over for starter Tyler Uberstine with one out in the top of the second, Mullins retired 15 of the 19 batters he faced over 5 2/3 scoreless frames of relief. The 23-year-old left-hander allowed three hits and one walk while striking out five. He threw 70 pitches (44 strikes), eliciting 12 swings-and-misses as the Drive ultimately fell to the Winston-Salem Dash, 1-0, at Fluor Field.
In 22 appearances (17 starts) for Greenville this season, Mullins posted a 3.94 ERA and 4.12 FIP with 118 strikeouts to 42 walks over a staff-leading 89 innings. That includes a 3.33 ERA (3.97 FIP) with 28 strikeouts to eight walks in his final five outings (24 1/3 innings) dating back to August 10. Opposing hitters batted just .221 against him during that stretch.
Among the 27 pitchers who threw at least 85 innings in the South Atlantic League this year, Mullins ranked second in strikeouts per nine innings (11.93), third in swinging-strike rate (15.1 percent), fourth in strikeout rate (30.3 percent), fifth in xFIP (3.70), eighth in batting average against (.223), 10th in groundball rate (42.7 percent), 12th in FIP and WHIP (1.29), and 13th in ERA, per FanGraphs.
Mullins, who turns 24 on Saturday, was selected by the Red Sox in the 12th round (369th overall) of the 2022 draft out of Auburn. The Tennessee native signed with the club for $97,500 but did not make his professional debut until last August as he was still recovering from Tommy John surgery. He is currently regarded by SoxProspects.com as the No. 26 prospect in Boston’s farm system, which ranks 13th among pitchers in the organization.
Listed at 6-foot and 194 pounds, Mullins throws from a three-quarters arm slot and incorporates a high leg kick into his delivery. As noted by SoxProspects.com’s director of scouting Ian Cundall, who saw Mullins pitch in-person on August 23, the undersized lefty sits between 91-94 mph and tops out at 95 mph with his fastball. He also mixes in an 81-85 mph sweeping slider and a deceptive 83-85 mph changeup.
Should he remain with the Red Sox through the winter, Mullins is projected by SoxProspects.com to make the jump to Double-A Portland in 2025. He has intriguing potential as a pure reliever but will need to shore up his command and control to remain in a starting role moving forward.
