I looked at Boston’s loss to Dallas and saw stretches of promise mixed with periods of gloom. Danny Ainge looked at the same game and thought it was simply “miserable.” He believes the Celtics look old through nine games and threatened to make moves if the Celtics continue to lose games. (WEEI)

Asked if he would consider major changes to the roster if the Celtics don’t show significant improvement between now and the trading deadline, Ainge acknowledged that he would have to consider the possibility.

“I’m committed to the guys as long as they’re going to perform, but they’ve got to perform,” he said. “They’ve got to show they have an opportunity to win. Otherwise, I’ve got to at least make an effort to go another direction.”

Ainge pointed to two areas that have haunted Boston for years as places the team needs improvement: offensive rebounding and late-game scoring. The Celtics tallied zero second-chance points against the Mavericks and went through a scoring drought near the end of the fourth quarter before Paul Pierce woke them from their offensive slumber.

“I think there’s two things that sort of stand out. I’m not taking a nine-game sample. I’m looking at what has been our pattern, and what has been our weakness, over the last three years with this group of guys,” said Ainge. “For three years now, we have been the worst offensive rebounding team in basketball. The second thing is, the execution of our offense, our offensive efficiency in the last five minutes of the game, I think those two things have got to be improved. I don’t necessarily know why that hasn’t happened. It’s not just personnel, because we’ve had a lot of good offensive rebounders on this team.

“I just don’t understand why we’re last. We don’t have to be first,” he added. “It’s not based on shooting percentage. When we talk about offensive rebounding, we’re talking about offensive rebound percentage. If we shoot 40-for-80, there’s 40 rebounding opportunities when we miss and we get eight of those, that’s 20 percent. That’s what we’re playing at. It’s not enough. We’ve got to get up to 25 percent, to the middle of the pack.”

But Doc Rivers urges you not to give up on Boston yet, even if the Celtics haven’t shown many (or really, any) signs of being elite yet. (ESPN)

“Well, we’ll have to find that out. I think we are,” he said after Thursday’s practice at the Celtics Training Center at HealthPoint. “But, obviously, we’re 4-5 right now. Our record says we’re not [an elite team]; We say we are. I’m just going to warn you, it’s nine games. Don’t jump off the bridge yet. I can feel you jumping off.

“What I’m saying is, it’s early guys. Coaches always worry about their teams, that’s my job — concern [and] worry. That’s what it should be. If we were 10-0, I’d be concerned that we’re getting overconfident. We’re 4-5 and really haven’t beaten anyone yet. So we have to do that, eventually, if we want to be an elite team.” …

“We’re getting closer,” said Rivers. “Actually, I was more encouraged than discouraged. Now, the rebounding problem we have to fix, but a lot of the other things — defensively, we’re really good until we gamble. We lost 12 big points on gambles, and nine were down the stretch, which you can’t do. Which is what I meant about discipline. But, overall, I like some of the things we’re doing. We have to get better offensively and we have to start games better.”