Arizona's Lute Olson is stepping down as the school's men's basketball coach, a source has told ESPN college basketball analyst Dick Vitale.
Associate coach Mike Dunlap will take over the head coaching duties on an interim basis, the source told Vitale. The timing of Olson's announcement is uncertain, Vitale reported later Thursday. Vitale reports that the move is imminent.
Arizona spokesperson Tom Duddleston said Thursday morning that Olson hasn't informed the administration that he is resigning. Duddleston said he went to his superiors and was told, "no way," in response to the report.
"We're not making any announcement to that effect," Duddleston said. "At this moment there is nothing going on."
The fathers of two Arizona recruits told the Arizona Daily Star and Tucson Citizen that they had been informed that Olson was stepping down by Dunlap and fellow Arizona assistant Reggie Geary. Abdul Gaddy, Sr., father of point guard Abdul Gaddy, and Solomon Crawford, father of forward Solomon Hill, said they had been told the news.
"He just told me it was official -- that Lute was out, that Dunlap was interim," Crawford said, according to the Daily Star.
Olson returned to the Arizona program after taking a year-long leave of absence, which the school said was not taken for health reasons.
An ESPN.com reporter was at Monday's Arizona practice in Tucson and Olson was coaching on the floor and in good spirits.
Calls to Olson and Arizona athletic director Jim Livengood weren't returned Thursday morning.
Olson missed a practice Wednesday and an appearance at a local Rotary club for health-related reasons, the Daily Star reported.
Geary, who replaced Olson at the Rotary event, said Olson had laryngitis.
Dunlap, who handled practice on Wednesday, said the 74-year-old Olson wasn't feeling well.
"It happens to everybody," Dunlap said, according to the Daily Star.
Livengood agreed, saying in the Daily Star: "He's just sick."
On the day before practice began last week, Olson told the Tucson Citizen that he was "excited to get on the court" and get going.
Olson has a career record of 780-280 at Long Beach State, Iowa and Arizona. He's 589-188 since heading to Arizona for the start of the 1983 season.
Arizona won the 1997 NCAA national title. His 27 NCAA Tournament appearances as a coach are one behind Bob Knight for the all-time record. His streak of 24 straight tournament appearances between 1985-2008 is second all-time to North Carolina's 27 (between 1975 and 2001).
Entering the season, Olson was second behind Mike Krzyzewski of Duke for most wins among active NCAA Division I men's coaches. He was inducted into the Basketball Hall of Fame in 2002.
ESPN.com's Andy Katz contributed to this report.