Bellaire, Texas native Josh Blum attended the Emery Weiner School in Houston, where he lettered in both baseball and football for all four years. During his time with the Jaguars, he achieved an impressive 0.75 ERA with 166 strikeouts in 92.0 innings. Although a promising right-handed pitcher from Texas and noticed by scouts, Blum went undrafted and chose to honor his commitment to the University of Southern California.
In 2022, Blum played 11 games out of the bullpen for the Trojans, posting a 12.10 ERA in 9.2 innings, with 9 hits allowed, 14 walks, and 12 strikeouts. His sophomore year in 2023 was much more successful under new head coach Andy Stankiewicz. Blum took on a more significant role in the bullpen, achieving a 3.34 ERA in 32.1 innings over 30 relief appearances, with 24 hits allowed, 12 walks, and 40 strikeouts. That summer, he also pitched for the San Luis Obispo Blues in the California Collegiate League before returning to USC for his junior season. As the team closer, Blum excelled with a 1.87 ERA in 33.2 innings over 27 appearances, allowing 18 hits, 11 walks, striking out 45, and closing out 10 games.
The 6’1″, 195-pound right-hander now throws from a low three-quarters, nearly sidearm slot, having lowered his arm slot from a higher position since attending USC.