Milwaukee Mayor Tom Barrett expressed concerns Monday about the actions of Milwaukee police in the arrest and tasing of Bucks rookie Sterling Brown.

His comments came as the Police Department braces for a backlash when it releases the video of Brown's arrest. 

Brown did not appear combative or threatening when officers questioned him about a parking violation in January, according to two sources who have watched the video. The sources asked that their names not be used because they weren't authorized to speak publicly about it.  

Barrett did not go into detail about the video, which could be made public as soon as Wednesday, but he repeatedly said he had concerns about the actions of police personnel seen on the video. He said Police Chief Alfonso Morales had a similar reaction. 

"I'm going to let the release of that speak for itself, but yes, I definitely have concerns after watching that video," Barrett said at a news conference. 

Police officials have been preparing community leaders for the release of the body-camera footage by showing it to selected local officials, including a closed session of a Common Council committee. Bucks officials have reportedly watched the video as well. A Bucks spokesman declined to discuss the matter Monday. 

"This could be bad," said one source who watched the video. "The player doesn't appear to be provocative at all."

Brown's arrest did not result in criminal charges against the NBA guard and prompted an internal investigation on the police response, including the role of supervisors.