Jaylen Brown is eligible for a supermax extension worth $270 million over five years with the Boston Celtics this offseason, but no deal has been reached so far this offseason.

"The side are talking," said Brian Windhorst on Sports Center. "This is obviously a very important, fragile deal. I know that there's interest in both sides to get something done. I would expect it to head in that direction.

"The one thing to point out: if Jaylen Brown gets extended on this deal for a year. For any deal at all. He cannot be traded for a year. For any deal at all. He's prohibited from being traded. So the Celtics probably want to make sure all their business is locked down before going into this."

Windhorst was asked to explain why he described the situation as "fragile."

"I think it will get done, but he's eligible for up to 35 percent of the salary cap, but he doesn't have to get that. The Celtics can negotiate on that. They can negotiate on the player option. They can negotiate on several things... There's aspect within the deal you have to negotiate."