From riding young horses in Argentine practice chukkers to preparing award-winning ponies in the United States, Diez’s uncommon judgment and hands-on training skills have defined an international career.

In polo, the spotlight generally follows the players who raise the trophy and the ponies that deliver exceptional performances. Less visible is the work that comes before a horse enters the field: patient schooling, physical conditioning, careful feeding, and an understanding of each animal’s temperament. Turning a young prospect into a reliable tournament mount requires exceptional judgment, patience, and horsemanship. For Argentine trainer Julián Diez, those skills have been the foundation of an international career spanning nearly two decades.

Early Foundations and International Experience

Diez began his professional career in 2007, working with young polo horses at Warsaw Polo Club in Poland. He later gained experience in Argentina and Austria, preparing horses for patrons and teams associated with Benedikt Abensperg und Traun, Peter Godanyi, and Robert Kofler, including horses played by Amadeus Polo Team.
His work in those years included horses such as:

• La Overa
• La Niña Bonita
• La Martina
• El Batallador
• La Valentina
  These were ridden by Abensperg und Traun and Matías ‘Vizcacha’ Benoît during Argentina’s 2009 polo season. Other early projects included El Cien Mil and La Mínima. Diez participated in La Mínima’s initial breaking and development before the mare was acquired by Argentine polo player Juan Monteverde. She subsequently became one of Monteverde’s playing horses and received Best Playing Pony recognition at the America Cup in Santa Barbara, California—an early example of the lasting impact careful development has on a horse’s competitive future.

A Hands-On Approach in Argentina

In Argentina, Diez has taken a particularly hands-on approach to schooling new and inexperienced polo horses: he has personally ridden them in polo practice chukkers as part of their training.
Riding a young horse in a practice setting allows him to assess:

• Its reactions to the movement and pace of play.
• Its confidence around other horses.
• Its responsiveness to the rider.
  He uses these observations to shape further schooling and conditioning. The purpose is to develop the horse through practical experience, not simply to give it exercise.

Tailored Development with Juan Monteverde

Since 2014, Diez has worked closely with Monteverde, training, schooling, and conditioning his polo horses in Argentina and the United States.
One of his distinguishing abilities is recognizing precisely what each horse needs: a horse requiring greater confidence calls for a different approach from one that needs better conditioning, responsiveness, or manageability. Diez adapts feeding programs, physical preparation, and schooling to each animal’s condition, temperament, and playing requirements. His extraordinary training ability is reflected in this individualized judgment, rather than in any single, fixed routine.
An important chapter in that experience unfolded at Mt. Brilliant Farm in Kentucky. Between 2020 and 2022, while Monteverde played professionally with Mt. Brilliant Farm Polo, Diez helped prepare horses used by Monteverde and the team, including Goldilocks, Hellcat, Goodfort, Noel, and La Marca.
He contributed to Goldilocks’ development from a young prospect into a finished polo mount; she later competed at U.S. Open level with Facundo Pieres and was taken to Argentina for the 2023 Argentine Open, illustrating the long-term importance of skilled early development.

Recent Successes and Best Playing Pony Accolades

More recently, Monteverde’s horses under Diez’s preparation have made their mark in United States competition while being played by Bob Parr, owner and patron of RBC Polo Team, and professionals including Juan Sánchez. Their results offer a clear illustration of the value of this specialized work behind the scenes.

1. Paisana

• Regional President’s Cup (2025): Named Best Playing Pony at Foxlease Polo Club in Upperville, Virginia, played by Juan Sánchez as RBC won the 4- to 8-goal competition. The award was featured in POLO magazine alongside Sánchez, Parr, Diez, and Martín Silva.
• Beverly Invitational 10 Goal (July 2026): Again received Best Playing Pony honors while played by Sánchez, proving her sustained competitive form across separate seasons.

2. Toby

• Palm Beach Invitational 6 Goal (January 30, 2026): Recognized as Best Playing Pony in the final while played by Bob Parr. Diez had prepared Toby since 2023 using individual feeding, conditioning, and behavioral exercises.

3. Pharma (Listed as ‘Parma’ in USPA coverage)

• Regional President’s Cup (February 27, 2026): Received the Best Playing Pony award at Beldi Polo Club in Florida when RBC won the championship under Bob Parr.
• USPA Regional President’s Cup — July 24, 2026: Added another Best Playing Pony distinction in Palm Beach.

The Unseen Art of Horsemanship

Each horse has presented a different challenge. Paisana’s sustained competitive form, Toby’s development into a prize-winning mount, and Pharma’s improved suitability for play reflect the broad range of Diez’s technical abilities.
The common thread is not a standard formula, but his capacity to:

• Assess temperament and performance accurately.
• Adjust workloads and schooling dynamically.
• Build the consistency and confidence a polo horse needs under pressure.
  Championship titles belong to the teams that win them, and Best Playing Pony awards recognize the horses that earn them. Yet those performances also depend on skilled professionals whose contributions are often unseen. From riding young horses in practice chukkers in Argentina to preparing established competition mounts for Juan Monteverde in the United States, Julián Diez has built his career on the difficult, patient work of developing horses long before they enter the field. It is in that combination of close observation, specialized knowledge, and hands-on horsemanship that his extraordinary abilities as a trainer are most clearly seen.