During the 2023-24 season, Alonso was elevated to a full-time assistant coach. He played a crucial role in the teams success, helping lead the Crimson to a 22-7 record, a second consecutive trip to the NCAA Sweet 16, and its third straight Ivy title. He was instrumental in leading All-Ivy and All-American level talent throughout the season. Cooper Williams '27 (first team singles and doubles), Henry von der Schulenburg '24 (first team singles), Daniel Milavsky '25 (first team doubles, second team singles), and Ronan Jachuck '24 (second team singles) all received All-Ivy nods under the assistance of Alonso while Williams also earned All-America honors following a quarterfinals run in the NCAA Individual Championships singles draw.
In his first year with the Crimson, Alonso played an instrumental role in the Crimson first 20-win season since 2018. In 2022-23 the Crimson reached a high of No. 7 in the nation, advanced to the Sweet 16 as a part of its 28th NCAA Tournament appearance, and won its second straight Ivy League title while going undefeated in league play. Alonso was also instrumental in the coaching of several All-Ivy honorees in Harris Walker '23 (first team singles and doubles), Henry von der Schulenburg '24 (first team singles), Daniel Milavsky '25 (first team doubles, second team singles), Ronan Jachuck '24 (second team singles and doubles), and Steven Sun '23 (second team singles).
Before joining Harvard as the men’s tennis volunteer assistant coach prior to the 2022-23, Alonso served as a volunteer assistant coach for the men’s and women’s tennis teams at Division II McKendree University during the 2021-22 season. In his team with McKendree, Alonso helped the team to its first ever GLVC conference championship, the school’s best season record (21-3), and its highest NCAA ranking ever (22).
Alonso hails from Albacete, Spain and played his collegiate tennis at Division I St. Louis University from 2014-18. Alonso finished his career at SLU tied for 10th in doubles wins and 15th in singles wins. Throughout his time at SLU, he received Atlantic 10 All-Conference honors and consistently finished in the top 3 for doubles wins, singles wins, and total wins.
In the classroom at St. Louis University Alonso received a Bachelor of Science in Exercise Science and later a Master of Athletic Training. Alonso was a two-time member of the Atlantic 10 Commissioner’s Honor Roll during his junior and senior year. Recently, Alonso also received his Director of Racquet Sports Certification from the University of Florida.
Juan has worked at several different academies and clubs and served as a private tennis coach throughout Saint Louis, Missouri. His experience also includes working at the prestigious Juan Carlos Ferrero Equelite tennis academy in Spain alongside world renowned ATP and WTA coaches.
