Michigan investigating allegations of excessive practice time in its football program

Martin did not return messages left at his home and office Sunday, but said in the statement the university will have more to say when it has completed its investigation.

"We are committed to following both the letter and the intent of the NCAA rules and we take any allegations of violations seriously," he said.

In a report that appeared online Saturday, several unidentified current and former players told the Detroit Free Press they were required to spend long Sundays at the football building last season and worked out in excess of the eight hours permitted by NCAA rules during the last two offseasons.

Athletes are allowed to devote additional time to their sports, as long as it's of their own choosing.

Former Michigan receiver Toney Clemons confirmed the report in a story Sunday on ESPN.com.

"The allegations are true," Clemons said. "Nothing is fabricated or exaggerated in that story. I was there on Sundays from 10 a.m. to 10 p.m. or 11 a.m. to 10 p.m. depending on if guys needed treatment. You were there daylight to nighttime."

Michigan coach Rich Rodriguez denied any wrongdoing in a statement.

"We know the practice and off-season rules and we stay within the guidelines," Rodriguez said. "We follow the rules and have always been completely committed to being compliant with all NCAA rules."

Associate athletic director for compliance Judy Van Horn said Michigan performs "in-person spot checks" of practice in and out of the season.

"We have not had any reason to self-report any violations in this area with any of our sports," she said in a statement.