Waldron signed with the Indians and made his professional debut with the rookie–level Arizona League Indians before he was promoted to the Low–A Mahoning Valley Scrappers. Over 45+2⁄3 innings between the two teams, he went 4–0 with a 2.96 ERA.[8] He did not play a minor league game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[9]
Waldron returned to San Antonio to begin 2022 and was promoted to the Triple–A El Paso Chihuahuas in late June.[14] Over 25 starts between the two teams, he went 5–10 with a 6.26 ERA and 96 strikeouts over 113+2⁄3 innings.[15] To open the 2023 season, he was assigned to El Paso.[16] In 14 games (12 starts), Waldron struggled to a 1–6 record and 7.02 ERA with 75 strikeouts in 66+2⁄3 innings pitched.[17]
On June 23, 2023, the Padres announced they would be promoting Waldron to make his major league debut the next day as the team's starting pitcher.[18] He made his debut at Petco Park against the Washington Nationals. Waldron pitched 4+2⁄3 innings, allowing four hits and two runs (both earned), while striking out two Nationals batters in a 2–0 loss. He was the first pitcher to throw a knuckleball in a major league game since Baltimore Orioles’ pitcher Mickey Jannis in June 2021.[18] He was optioned back to El Paso the next day.[19]
Waldron was recalled to the majors several times throughout the remainder of the 2023 season, making eight appearances (six starts) going 1–3 with a 4.35 ERA and 31 strikeouts over 41+1⁄3 innings.[20]
Pitching style
Unlike other recent knuckleball pitchers like R. A. Dickey and Tim Wakefield—both of whom relied heavily on throwing knuckleballs—Waldron's primary pitch is a four-seam fastball. His off-speed pitches are a slider and a knuckleball.[11]
Personal life
Waldron's twin brother, Mike, also played on the Nebraska baseball team.[21]