From Comcast SportsNetLUBBOCK, Texas (AP) -- An ambulance was sent to the home of Texas Tech coach Billy Gillispie for the second time in 10 days while he remains on leave as the school investigates his leadership of the program.Lubbock Police Sgt. Jeff Baker said Tuesday that the emergency call came from Gillispie's home around 6 p.m. Monday and that an ambulance was sent.A spokesman for University Medical Center, where Gillispie earlier spent six days this month, said Gillispie did not come there. A spokeswoman for the other hospital in Lubbock said Gillispie was not brought there.Gillispie, in a text message to The Associated Press late Tuesday, said he would be treated for high blood pressure "amongst other things," at the Mayo Clinic in Rochester, Minn.Texas Tech spokesman Blayne Beal said Gillispie told athletic director Kirby Hocutt he was going to the Minnesota medical facility for treatment."We hope Billy Gillispie has a full recovery, but we cannot wait forever as we have a basketball team that starts practice soon," Hocutt said in a statement."In the meantime, associate head coach Chris Walker will assume the responsibility for day-to-day operations of our men's basketball program. Coach Walker will help ensure that leadership and accountability will be in place for our student-athletes, assistant coaches and staff."Gillispie is on indefinite sick leave and Hocutt said he is no longer making day-to-day decisions for the basketball program so he can focus on his health."Nor is he to engage with our program in any way until he and I have a chance to sit down and talk face to face," Hocutt said.On Aug. 31, Gillispie called 911 and was taken to the medical center. It was the same day he was supposed to meet with Hocutt to discuss allegations he had mistreated his players. The school has reported excessive practice-time violations to the NCAA and reprimanded Gillispie in January.Gillispie told the Lubbock Avalanche-Journal on Aug. 31 that he felt like he was having a heart attack or a stroke when he called 911. Doctors told Gillispie his blood pressure was dangerously high, the paper reported.The school penalized itself for the practice overage, docking twice the number of hours that Gillispie had exceeded during a two-week period in October or 12 hours and 20 minutes. An unidentified assistant coach was also reprimanded.The NCAA allows 20 hours of practice per week.Hocutt said the school continues to "work through the process" of looking into allegations players brought to him Aug. 29. Gillispie's assistant coaches, with Hocutt's oversight, are handling the program for now.Hocutt did not put a timetable on when he and Gillispie would meet."I can't anticipate given the other issues related to his health," he said. "With basketball season officially starting practice in a month, the sooner the better."Hocutt has declined to say whether Gillispie could be fired. He has said he was "very troubled" by the information players had given him.Hired in March 2011, Gillispie came to Texas Tech after two years out of coaching. The school and fans had hoped he could orchestrate another remarkable turnaround, like the ones he put together at UTEP and Texas A&M.He went to Kentucky in 2007 but the school fired him in 2009 after it went 40-27 in his two seasons and missed the NCAA tournament for the first time in 17 years.