Arizona State hockey player Matthew Mayich remains hospitalized in critical condition nearly a month after collapsing during a preseason team workout, as new details raise questions about the training session and the circumstances surrounding it.
Mayich, a 21-year-old defenseman and St. Louis Blues prospect, collapsed last month during a demanding outdoor conditioning session at Sun Angel Stadium.
A lawyer representing Mayich’s family has said the player suffered exertional heat stroke that caused a lack of oxygen to his brain, leaving him unconscious and unlikely to recover.
The incident has prompted scrutiny of Arizona State’s men’s hockey program, while the university reviews the circumstances of the workout and Arizona State University Police conducts its own probe.
The university has characterized the police inquiry as standard and has described its internal process as a review rather than an investigation.
New Details Emerge About Workout
The Aug. 20 session marked the team’s first official activity ahead of the new season and differed significantly from Arizona State’s previous preseason conditioning.
Instead of being directed by the hockey coaching staff, the approximately 45-minute workout was led by Tim Ziesel, a former Green Beret who had previously spoken to the team. Head coach Greg Powers watched from the sideline as players worked through a series of exercises and running drills.
According to The Athletic’s reporting, which cited people who witnessed the workout or were briefed about it, players performed exercises including push-ups, squats, flutter kicks, bear crawls and sprints.
Additional running was assigned at different points when exercises were not performed as directed. At least two players reportedly vomited during the session.
Mayich showed signs of struggling before his eventual collapse, according to witnesses cited in the report. During a bear-crawl exercise, one witness said he appeared disoriented and nearly fell after standing. Later, players were instructed to carry teammates across the field as part of another drill.
The workout ended with players divided into groups for a relay that required them to sprint while carrying a medicine ball. During his turn, Mayich reportedly stumbled, dropped the ball and fell. He attempted to get back to his feet more than once before collapsing again.
Emergency Response and Hospitalization
Teammates and staff quickly gathered around Mayich after his collapse. However, he remained in the sun for several minutes before players carried him into the shade, where an athletic trainer attempted to cool him using water, towels and an ice pack.
Tempe Fire Medical Rescue responded to the stadium at 8:31 a.m. During the emergency response, the situation was described over the radio as a serious heat emergency. Mayich was subsequently transported to a hospital, where he has remained in critical condition.
Rob Carey, an attorney representing Mayich’s family, has said the family believes Mayich suffered exertional heat stroke during the workout. Carey said the resulting oxygen deprivation caused severe damage to Mayich’s brain and that he is unlikely to recover.
The team returned to practice the following morning with Powers present, while Ziesel was no longer leading the session.
Questions Surrounding the Hockey Program
The circumstances surrounding the workout have brought additional attention to Powers and the culture within Arizona State’s hockey program.
Powers had publicly expressed frustration with his team following the 2025-26 season, during which Arizona State lost 10 of its final 12 games and failed to reach the postseason.
In a May podcast appearance, he criticized the team’s toughness and said players had failed to respond properly to adversity, according to The Athletic.
The new reporting also describes concerns from current and former players about Powers’ coaching methods. Some former players portrayed him positively as a strong motivator who helped build Arizona State hockey into a Division I program and continued supporting players after they graduated.
Others described a more volatile environment, including incidents in which Powers allegedly damaged equipment and sent messages criticizing players’ effort and performance.
Ziesel’s attorney told The Arizona Republic that the former Green Beret was brought in to lead the planned three-day training session through a handshake agreement with Powers and other staff members and was never asked to sign a contract, an arrangement that appears to conflict with university policies.
Players Await Answers as Season Approaches
Arizona State has not publicly announced a final determination about what happened during the workout. Athletic director Graham Rossini told players’ parents in early September that the university expected to share initial findings from its review soon.
Meanwhile, the incident continues to weigh heavily on Mayich’s teammates. Players attended a Sept. 3 vigil for him at the hospital, and the hockey program later publicly said the Sun Devil community was keeping Mayich and his family in its thoughts and prayers.
Some players have privately expressed anger about the workout and discomfort that Powers remains in charge while authorities examine what happened, according to the report. Others reportedly fear that speaking publicly could have consequences for their hockey careers.
Arizona State’s season is scheduled to begin Oct. 2. But with Mayich still hospitalized and questions surrounding the workout unresolved, the program enters the season facing an issue far larger than its performance on the ice.
Ziesel has remained publicly silent following the incident.
New Details Emerge About Workout That Left ASU Hockey Player in a Coma