The issues Deron Williams faced during his tenure with the Brooklyn Nets were both physical and mental, according to sources close to the situation.

Williams was acquired by the Nets in 2011 in a costly trade and he signed a new deal in 2012 worth more than $100 million.

"He played a lot better with less than he did with more, when he was more of a focal point," former Nets assistant GM Bobby Marks said.

Williams' leadership was also criticized by Paul Pierce.

"Before I got there, I looked at Deron as an MVP candidate," Pierce said. "But I felt once we got there, that's not what he wanted to be. He just didn't want that.

"I think a lot of the pressure got to him sometimes," Pierce said. "This was his first time in the national spotlight. The media in Utah is not the same as the media in New York, so that can wear on some people. I think it really affected him."

Williams is getting a fresh start this season with the Dallas Mavericks.