To hear Jason Terry talk about him, the Celtics aren’t getting a run-of-the-mill, 10-day guy in Terrence Williams, a fellow Seattle native.

“I know him well,” Terry said of the 6-foot-6, 220-pound guard, who is expected to be signed to a 10-day contract. “He’s one of the young kids who grew up in that area that had tremendous talent. He’s a freakish athlete. When you talk about athleticism, he’s right there with LeBron (James) and (Kevin) Durant and these guys that are high flyers. He’s right up there with him.

“He’s very athletic, can handle the ball. He’s highly skilled. It’s just been a matter of him getting on the right team, surrounded by veterans that he can learn from. I believe he can definitely help us.”

Williams, the 11th overall pick in the 2009 draft out of Louisville, has bounced around from New Jersey to Houston to Sacramento. He spent 10 days working out at the Celtics facility last September but couldn’t crack a tight roster. When he was cut by Detroit a month later, Williams went to China.

The major knock on him in the NBA has been his attitude and approach to the game, but Terry believes Williams can get past that with the Celts.