ASU head hockey coach placed on leave after player's collapse during practice

Arizona State University’s handling of a hockey player’s collapse during a summer workout is drawing scrutiny across Arizona, including from state lawmakers who are asking for an investigation outside the university. Matthew Mayich, a 21 year old player from Stoney Creek, Ontario, and a 2026 St. Louis Blues draft pick, has remained in a coma for more than a month after becoming unresponsive during an outdoor conditioning session in Tempe. ASU head coach Greg Powers has now been placed on administrative leave, but the player’s family and seven anonymous teammates say the move does not go far enough to protect athletes or establish what happened.

Mayich collapsed on Aug. 20 at Sun Angel Stadium, during the team’s first official workout of the 2026 to 27 season. He had arrived in Arizona only eight days earlier. His family’s attorney, Robert Carey, has said Mayich suffered exertional heatstroke that deprived his brain of oxygen and left him with no meaningful chance of recovery. The family previously called for the removal of the entire coaching staff involved in the workout, arguing that an independent review cannot proceed while players remain under the authority of coaches who controlled their playing time, scholarships and roster status.

The National Collegiate Hockey Conference announced Powers’ leave after concerns raised by players became public. The conference said student-athletes’ complaints should be fully heard and reviewed without prejudging the outcome, adding that their health takes priority over hockey. Powers, who has been ASU’s only head coach since the program moved to NCAA Division I competition in the 2015 to 2016 season, said the leave should allow an independent and thorough review. He said he would cooperate, respected the players’ ability to speak candidly and continued to hope for healing for Mayich and his family.

Assistant coach Mike Corbett is scheduled to lead the Sun Devils in their season opening games at Lindenwood University, while ASU has said an interim coach will be named. The players had asked for an interim coaching staff before the Oct. 2 opener, and identified former Coyotes captain Shane Doan as a possible candidate. Carey has said that leaving Powers’ longtime friend in charge of the locker room would not resolve concerns about retaliation. He has urged ASU to give the interim coach authority to remove anyone who could intimidate or punish players who participate in the investigation.

The seven players submitted a 26 page letter to ASU President Michael Crow on Sept. 28 through attorney Timothy Casey. They said the university’s initial review, led by Senior Vice President James Rund and delivered to Crow on Sept. 21, failed to compare the workout with ASU’s own safety policies or identify who was responsible for following them. The players said the workout lasted more than 75 minutes, from about 7:05 a.m. until Mayich collapsed around 8:23 a.m., rather than the approximately 45 minutes described in the university’s account. They also said the team had only one brief water opportunity, roughly 35 to 45 minutes into the session, and that only the first eight or so players to finish a drill reached the bottles.

According to the players, Mayich never received water. They said he showed signs of distress well before the final medicine ball relay, including disorientation, difficulty carrying a teammate and the need to lean on another player to remain upright. The letter describes other players vomiting or dropping to their knees, while additional exercise was allegedly assigned as punishment for falling behind or miscounting. The workout was led by Tim Ziesel, a former Green Beret who had been introduced to the program by an ASU booster. The players said he left after assigning the final relay, leaving ASU coaches and an athletic trainer supervising when Mayich’s condition worsened.

The students also disputed the university’s account of the emergency response. They said Mayich stumbled, collapsed more than once and eventually stopped responding, with his lips turning gray. They reported that he was sat upright twice, lay in direct sunlight for several minutes and was treated with squirt bottles, a few towels and less than a minute of warm water from a garden hose. The required cold water immersion tub was not on the field, they said, and nobody used the tub inside Mullett Arena. They also said no core temperature was taken. ASU’s report, by contrast, described staff as applying iced towels and cool water and said Mayich remained on the ground.

Questions also surround the outside instructor and heat acclimatization. ASU policy prohibits outside consultants from working with athletes before approval. The players said Ziesel had not been properly vetted, that no written training plan was reviewed by strength and conditioning staff and that certifications for first aid, CPR and AED use were not verified. They also challenged the university’s conclusion that Mayich had received enough outdoor exposure to be acclimatized. The players said his earlier outdoor sessions consisted only of a few brief periods pushing weighted plates between stretches indoors, rather than sustained exercise in Arizona heat. They further questioned the university’s use of an off-site weather station and a description of mostly cloudy conditions, saying the workout took place in direct sun and no on-field heat measurements were recorded.

After Mayich was taken to the hospital, the players said Powers described the injury as “just a little heat stroke” and told them Mayich needed an intravenous treatment. They said the team practiced the next day after being told he would be fine. The players submitted their letter anonymously because they feared consequences from the coaches, although Casey said he holds signed statements and has verified their identities. They requested written protection against retaliation, an outside investigator, findings on policy violations and temporary coaching leadership while the review continues. They also said some players gave statements to ASU Police without a parent or lawyer present and that those interviews were provided to the university’s internal review without prior notice.

The controversy has prompted calls beyond the hockey program. Arizona House Education Committee Chairman Matt Gress and Senate Education Committee Chairwoman Hildy Angius asked the Arizona Board of Regents to retain an independent investigator, saying ASU should not investigate its own conduct and decide whether anyone should be held accountable. U.S. Senators Mark Kelly and Ruben Gallego also called for an independent examination. Kelly said Mayich’s family and the teammates who came forward deserve answers, while Gallego said the allegations about intense exercise in Arizona heat and a lack of water would be unacceptable if confirmed. Carey has separately asked Maricopa County Attorney Rachel Mitchell to open a criminal investigation. ASU has said it has nothing further to add, while the NCHC said it will remain in contact with the university about the review and measures to support and protect its athletes.