via Boston Globe :
Paul Pierce reacted to warnings by coach Doc Rivers that roster changes will be imminent if the Celtics do not play better. Pierce said they are straying from the game plan, and that the Celtics are not at the correct mental state.
It was difficult for Paul Pierce to admit, but with his team having a 20-21 record and four straight losses, he had to.
“I think we got pieces here,” the Celtics captain said before Tuesday night’s 95-90 loss to the Cavaliers. “We just got to come together. We got to figure this thing out. Can’t get discouraged.
“I think that’s the one thing this team lacks, that mental toughness, man. When we lose our confidence, I’ve never been on teams like that. We got to stay together, we got to play with confidence.
“Yeah, definitely, it hurts me to say that. It’s like I really sometimes don’t believe it.
“We get down on ourselves. We got to go out there and believe we can win every game. It’s tough sometimes.”