Coach Doc Rivers said yesterday the Celtics lack conditioning and toughness.

“You have to be in shape first,’’ Rivers said. “You can have all the intensity you want, and I think our guys do. But after three minutes and your lungs hurt, you’re no longer thinking about intensity, you’re thinking about survival. How can I get through this next five minutes? And then you’re not playing the same. So, we have to be in better shape.’’

“Some of it is we have to be tougher,’’ Rivers said. “Maybe that’s conditioning, as well.”

via Frank Dell-Apa of The Boston Globe