Jerry Kill had two more seizures Tuesday and knew it was probably time to end his 32-year coaching career. But the Gophers football coach, who has publicly battled epilepsy since 2005, wanted to push his tired body one last time.

He grabbed a whistle and headed to that evening's practice, watching his players steel themselves for Saturday's game against Michigan while coming to a final resolve.

"When I walked off the practice field," Kill said, "I feel like a part of me died."

He had coached his last practice.

Choking back tears, Kill, 54, announced Wednesday morning that he was retiring immediately, shocking fans across the state as he explained that he could no longer coach the way he wants because of his health issues.

With his wife, Rebecca, tearfully watching near the side of a university stage, Kill told a stunned audience that his seizures had returned, he hadn't slept more than three hours a night in weeks, he had quit taking some of his medication and that he doesn't "have any more energy."

"This is not the way I wanted to go out," Kill said. "But you all know about the struggles, and I did my best to change. But some of those struggles have returned, and I don't want to cheat the game."

Beth Goetz, the university's interim athletic director, named defensive coordinator Tracy Claeys the team's interim coach for the rest of the season. Goetz said the school will begin the search for Kill's permanent replacement "in due course."

"We are grateful for Jerry Kill's service," University President Eric Kaler said. "Our program is enormously advanced from where it was when he arrived."

Kill, who had previously resurrected programs at Southern Illinois and Northern Illinois, replaced Tim Brewster in December 2010, inheriting a team that went 3-9 and had been penalized three scholarship openings because of lagging academics.

Under Kill, the Gophers have gained back respect on and off the field. His teams went 29-29 in four-plus seasons, with the past two seasons featuring headline victories over Michigan and Nebraska and a Jan. 1 bowl game. Last season, Kill was voted Big Ten Coach of the Year after an 8-5 finish and Minnesota's first winning conference record (5-3) since 2003.

Kill also emphasized academics and led an effort that lifted the team's cumulative grade-point average from 2.4 to 3.0.

"He's held those kids accountable," Goetz said. "They've done great things in the classroom, tremendous things on the field, and he has set this university up for great success that will be remembered for years to come."

Seizures return

In 2005, Kill had a seizure on the sideline while coaching at Southern Illinois, and doctors subsequently discovered that he had kidney cancer. He beat that cancer and regulated his seizures to the point he could continue coaching.

In his first three seasons at Minnesota, Kill missed parts of four games because of seizures. He had a seizure on the sideline at halftime against Western Illinois in September 2013 and returned that week. But when a seizure kept Kill from traveling to the game at Michigan on Oct. 5, 2013, he took a two-week leave.

Claeys took over as acting head coach, but Kill resumed most of his duties and coached seven games from the press box before returning to the sideline for the second half of the Texas Bowl.

In October 2013, Kill pledged to be seizure-free long enough to be able to drive again — at least three months by Minnesota law — and he was back behind the wheel in February. This July, he said he hadn't had a seizure in more than a year and a half.

In August, the university gave Kill a contract extension through 2019, raising his salary for this year to $2.5 million. He was scheduled to make $2.9 million in the final year of the deal. With his retirement, Kill will walk away from most of that money — his contract calls for the school to pay him about $800,000 on his way out, according to a university spokesman.

"I've given every ounce that I have for 32 years to the game of football and the kids I've been able to coach," Kill said. "I've never stole from anybody. I'm not going to steal now."

Kill outlined the scope of his renewed health struggles, beyond the two seizures he suffered Tuesday.

"I went through a bad situation two years ago, and I'm headed right back there," Kill said. "I haven't slept. Two nights ago, my wife was up with me all night, and I slept one hour and came to work. The most sleep I've gotten over the last three weeks is probably three hours or less.

"She stays there and sits in a chair and watches me," Kill said, as Rebecca Kill wiped away tears. "That's what she did last night. Hell, that ain't no way to live. I've taken years off my life and hers. But we both say we'd do it again, wouldn't we? Damn right."

Kill has talked in the past about improving his diet, exercising more and getting proper rest in the quest to minimize his seizures. When he took his 2013 leave, he went to a doctor in Grand Rapids, Mich., who helped regulate his seizure medication.

"I listened to my doctor … somewhat," Kill said Wednesday. "But I knew our team needed some help. I tried some stuff I had to do. I took my own self off [medication] because I couldn't think the way I wanted think."

Kill didn't offer specifics on his medication routine or lapses, but he did add: "As my doctor says, 'You're crazy for not taking stuff before a game.' I said, 'I love this game, and I don't want to let our university down.' I want to win, but taking sleeping pills to sleep, you know, it ain't worth it."

What's next?

Kill's retirement adds to the uncertainties facing the university's athletic department. On Friday, the university plans to hold a groundbreaking on the $166 million Athletes Village project, an effort that Kill helped spearhead but has lagged on fundraising goals. Meanwhile, the athletics department is undergoing two investigations — one into sexual harassment complaints against former athletic director Norwood Teague, and a federal investigation on gender discrimination in Gophers athletics. The department also is considering extra training or education for the football team following a recent U report of a "concerning pattern of football player conduct" related to allegations of sexual assaults and harassment.

Kaler said the school would wait for the results of the Teague probe — expected soon — before launching the AD and football coaching searches.

Kill started his news conference by referring to his wife and their two grown daughters, Tasha and Krystal.

"My doctor told me it was in my best interest for my family and my kids, and hopefully grandkids someday, that if I didn't move on with my life that I may be a guy that don't think too good down the road."

Kill said he's not sure what he'll do Thursday or Saturday during the Michigan game, let alone for the rest of his life.

"I ain't done anything else," he said. "That's the scary part."

Kill believes the team is in good hands with Claeys and the assistant coaches, many of whom have been with him for 15 or more years.

"Walking off the field [Tuesday], I thought, 'Tracy and our staff can do a better job than I can,' " Kill said. "Because the kids … know when I'm not myself, and then that reflects on the team. … I don't have any more energy. None. I've left it all right here in the great state of Minnesota."