Texas Tech suspended Mike Leach on Monday while the school investigated complaints from receiver Adam James and his family about how the player was treated after a concussion.
James is the son of former NFL player Craig James, now a television sports analyst for ESPN.
Defensive coordinator Ruffin McNeill will be the interim coach when Texas Tech plays Michigan State in the Alamo Bowl on Jan. 2.
School officials declined to identify the player, but James' family released a statement to The Associated Press saying it was Adam.
A person with direct knowledge of the complaints told the AP that James, while unable to practice with a concussion, twice was forced to stand in a small, dark place for hours while the team practiced.
The person spoke on condition of anonymity because of the sensitive nature of the complaint.
James was injured Dec. 16 and the next day was diagnosed with a concussion by team doctors, the person said.
According to the person, James was sequestered at two consecutive practices:
_ On Dec. 17, James said Leach told trainers to put him "the darkest place you can find." James was sent to an equipment shed near the practice field, where a member of the athletic staff checked on James to make sure he did not lean against anything or sit on the floor. James said Leach told him that if he came out he would be kicked off the team.
_ When the team returned to practice two days later, on Dec. 19, James said Leach told trainers to "find the tightest, darkest place" for the player. James, in his street clothes, was put in an electrical closet inside the football stadium for hours, again monitored by a member of the athletic staff.
The James family contacted the university after the second practice, the person said.
Leach's attorney, Ted Liggett, disputed the account.
Adam James "claimed to have been hurt," was examined and diagnosed with a "mild concussion," Liggett told the AP.
"I believe that (Adam James) was a disgruntled student athlete that like many were not happy with their playing time," Liggett said.
He told ESPN.com that James "was placed in an equipment room as it was much cooler and darker" than the practice field. The second time, Liggett told ESPN.com, James was placed in a "press room with air conditioning and a stationary bike he could use."
McNeill, who will remain in charge of the team until the investigation is complete, declined to answer questions about the complaints after Monday night's practice in San Antonio. Players were not made available to the media.
"Mike's my friend. We've been friends for a long time, and I don't think right now is the right time to go into that," McNeill said.
He said Leach arrived with the team in San Antonio and that Adam James also was with the team, but not practicing.
McNeill said he was told Monday afternoon that he was taking over for Leach, then told the players shortly afterward.
"They were probably a little shocked, but at the same time, they did a good job of coming on the field and doing what I asked them to do. I was proud of that," McNeill said.
Craig James was scheduled to announce the Alamo Bowl, however, ESPN spokesman Josh Krulewitz said James will no longer work the game.
The James family issued a statement Monday saying their "son had been subjected to actions and treatment not consistent with common sense rules for safety and health."
"Over the past year, there has been a greatly enhanced recognition of the dangers of concussions and the potential for long term physical damage to players. At virtually every level of football coaching, cases where children and young men have sustained concussions have generated serious discussion of the importance of correct treatment and diagnosis."
There's been internal strife this season with the Red Raiders (8-4).
Leach chastised players after a loss to Texas A&M in October for listening to "their fat little girlfriends," and thinking the Aggies were a pushover. After the Red Raiders' loss at then-No. 12 Houston in September, Leach indefinitely suspended starting offensive lineman Brandon Carter for violating team rules.
That week Leach also banned his players from having Twitter pages after linebacker Marlon Williams posted a tweet that asked why he was still in a meeting room when "the head coach can't even be on time."
Leach led Texas Tech to the best season in program history last year, going 11-2. But he and the university were at odds for months over negotiations for a contract extension. In February, Leach and the school agreed to a five-year, $12.7 million deal that could keep him there through 2013.
If Tech terminates the contract, the school must pay Leach $400,000 for each year remaining on the agreement. There is no buyout amount.
Associated Press College Football Writer Ralph Russo and Associated Press Writer Paul J. Weber in San Antonio contributed to this report.