(CNN) -- San Francisco police say they are investigating an allegation of sexual abuse against 49ers wide receiver Michael Crabtree.
The inquiry comes as the San Francisco football team is preparing for an important playoff game.
"Michael Crabtree has been interviewed with his lawyer present and has cooperated in this investigation," a San Francisco police statement said. "Michael Crabtree has not been detained or arrested and has agreed to make himself available to investigators in the future."
The complaint is about an alleged assault that occurred in a San Francisco hotel Sunday morning, police said.
A day before, the 49ers scored a playoff victory, beating the Green Bay Packers at Candlestick Park in San Francisco.
Crabtree had two touchdowns in the game, continuing his sterling play that has propelled him to being the team's best wide receiver this year.
"We are aware of the allegation against Michael and understand that he has fully cooperated with authorities," 49ers General Manager Trent Baalke said. "The 49ers take such matters very seriously. We will have no further comment at this time as the legal process is ongoing."
The 49ers will play the Atlanta Falcons on Sunday with the winner going to the Super Bowl.