LUBBOCK, Texas -- Texas Tech fans had pinned their basketball hopes on Billy Gillispie.

He had turned around two other flagging programs in the state, and they hoped he would do the same for the Red Raiders.

They watched a difficult first year in which Texas Tech won just one Big 12 game. Now fans won't get a chance to see a possible turnaround similar to what the 52-year-old coach had done at UTEP and Texas A&M.

Gillispie, a West Texas native, resigned on Thursday, citing health concerns.

"Billy has decided to focus on his health, and we wish him a full recovery," athletic director Kirby Hocutt said in a news release. "We are proud of the young men that he has brought to this campus. Billy's decision allows him to concentrate on his well-being and allows us to turn our attention to preparations for the upcoming season."

Gillispie didn't immediately return a call or text from The Associated Press seeking comment.

Gillispie will be paid the remainder of this contract year, about seven months' worth, or about $467,000. Chris Walker, who took over day-to-day operations, will remain in that position until an interim head coach is chosen. Hocutt has decided on a two-week timetable to name an interim coach for this season, according to a school spokesperson.

Gillispie's resignation letter said he appreciated the opportunity to coach the Red Raiders, but that he needed to tend to his health, officials said.

The move came less than a month after the school announced it was looking into allegations of player mistreatment last fall by the veteran coach -- a sensitive topic at Texas Tech, given the 2009 firing of football coach Mike Leach after claims that he mistreated a player suffering from a concussion.

Hocutt, who declined to make further comment Thursday, earlier this month called the allegations "very troubling."

In January, the school reprimanded Gillispie and assistant coach Brooks Jennings after a review found the team had exceeded practice-time limits in 2011. The school reported the secondary violation to the NCAA and penalized itself by reducing the team's practice time by about 12 hours.

While all that was filtering out, Gillispie's health apparently was growing worse.

Twice in a 10-day span this past month, 911 calls were made from Gillispie's home. The first, on Aug. 31, came hours before he was to meet with Hocutt and led to a six-day stay in a Lubbock hospital. The two men never met to discuss the allegations.

Gillispie wasn't taken to the hospital after the second call on Sept. 10. But the following day, he left for the Mayo Clinic in Rochester, Minn., where he said he got treatment for kidney problems and abnormal headaches. Doctors there told him to avoid stress for 30 days.

Gillispie succeeded Pat Knight, who went 50-61 in his three-plus years. Knight had taken over after his father, Bob Knight, resigned in February 2008.

Five years ago, Gillispie was one of the hottest names in the college game and had reached a pinnacle: coaching at perennial powerhouse Kentucky.

That peak lasted just two years. He was fired from Kentucky in 2009 after going 40-27 in two seasons, and the Wildcats missed the NCAA tournament for the first time in 17 years. When he returned to coaching at Texas Tech two years later, he came cheap. He went from an annual salary at Kentucky of $2.3 million to $800,000 a year at Texas Tech, signing a five-year contract to succeed Pat Knight.

In late 2009, Gillispie and Kentucky settled lawsuits against each other, with the former Wildcats coach getting about $3 million with no admission of wrongdoing from the school. Six months after his firing, Gillispie sought treatment at John Lucas' substance-abuse program in Houston following his third arrest for drunken driving in 10 years.

Gillispie's first two years as a college head coach were at UTEP in the Western Athletic Conference. He made headlines there for the biggest turnaround in basketball history, taking the Miners from 6-24 in 2002-03 to 24-8 the following year.