LOS ANGELES (KABC) -- USC Athletic Director Pat Haden said a thorough background check was done before Steve Sarkisian was hired, and it revealed no potential problems with the coach.
Haden made his remarks at a news conference held Tuesday, one day after Sarkisian was fired, five games into his second season.
"Steve had both NCAA and USC background checks done, and we talked to dozens of people, head coaches, staff, friends and people who knew Steve well for many years, some for decades," he said.
Haden said Sarkisian was fired for failing to meet the school's standards and expectations. Offensive coordinator Clay Helton was appointed as interim head coach.
"We love coach Sark. He is a very, very good man and a good football coach," Helton said at the news conference.
He dismissed media reports that said Sarkisian's alcohol consumption habits were well known when he was coach at the University of Washingon. Haden nor the newly appointed coach would comment on what he characterized as personnel issues.
The athletic director said firing Sarkisian wasn't an easy decision.
"It was very difficult to terminate Steve Sarkisian, someone who I sincerely like as a person, as a coach," Haden described.
Haden did not go into details about what happened with Sarkisian this past Sunday, though some players have told ESPN the second-year coach showed up to a team meeting prior to practice while under the influence.
In August, Sarkisian apologized for a "drunken profanity-laced speech" during a pre-season pep rally. He said he made the mistake of mixing alcohol with medication.
VIDEO: Complete Steve Sarkisian news conference
Haden said it was clear "he wasn't healthy." Haden also addressed the media about his own future with the university.
"I know who I am. At the age of 62, I know what I stand for. I know what I've been asked to do when I was hired by President Nikias, and I think I've delivered some pretty good results," Haden said.
USC President C. L. Max Nikias released a statement Tuesday, emphasizing his support for Haden.
"Pat Haden has been doing an outstanding job in leading Trojan Athletics in the past five years and I want to take this opportunity to reiterate my unwavering support for him," the statement read.
Haden and Helton spoke after the Trojans went back to work in their usual morning practice. Players were not allowed to speak before or after practice. Defensive lineman Kenny Bigelow spoke out on Monday, defending his former coach.
"Sark wasn't a bad guy. He wasn't an alcoholic or anything like that. He loved this program and we loved him back and I just wish him the best," Bigelow said.
Bigelow also expressed his support for Helton, who steps in with experience. He also replaced Lane Kiffin midway through the 2013 season.
The Trojans take on rival Notre Dame on Saturday.
The Associated Press contributed to this report.