Rajon Rondo is only 25, but he’s already accomplished a lot in this league. He’s a two-time All-Star, he’s a championship starter, and he’s already put up six postseason triple-doubles. The sixth one, Friday night against the Knicks, was a 15-11-20 stat line reminiscent of vintage Magic Johnson.

Pretty much everyone is impressed. Everyone except Knicks coach Mike D’Antoni, who said Sunday that he still has some reservations.

“He’s a very good basketball player,” D’Antoni said. “Really good. But I’d like to see him play in Minnesota and see how he does. They’ve got three Hall of Famers out there.”

Rondo’s own coach fired back before Game 4 on Sunday, letting the world know what he thought of D’Antoni’s comments.

“Keep doing it,” Doc Rivers said. “If it’s going to make him play like this, I’m all for it.”

Rondo has averaged 18.3 points, 12.0 assists, 8.0 rebounds and 1.3 steals per game so far in this series. He’s led the Celtics to within one win of a first-round sweep of the Knicks. But D’Antoni keeps on running his mouth.

“It’s probably just a product,” Rivers said. “You play with those guys, that’s probably what you’re going to get. But I don’t think he could trade it. I think he enjoys playing with them. If there’s a negative side, I guess, that would be it — that no matter how you play, the question will be there.

“But someday, that’ll be answered too. I’ve got a feeling that he’ll answer them all in the way he’s answering them now.”

Rivers acknowledges that eventually those three Hall of Famers — Paul Pierce, Kevin Garnett and Ray Allen — will be long gone, and when that happens, we’ll all discover the truth about Rondo. But at the moment, that’s the farthest thing from Rivers’ mind.

“No offense, but I’m more curious about Game 4,” the coach said. “I don’t think a whole bunch about that.”