Miami Heat coach Erik Spoelstra admitted his team had been "pummeled" in the paint in their 109-94 defeat to the Denver Nuggets and had failed to respond to the challenge.

The Nuggets out-scored the Heat 60-34 in the paint and also won the rebound battle 58-33 meaning that Denver's miserly five of 18 three-point shooting didn't matter.

"They just pummeled us in the paint," Spoelstra said. "They didn't really have to shoot threes. They had, whatever, 60 in the paint. There wasn't a need to space the floor.

"We didn't offer much resistance….I thought offensively, we actually did get a lot of opportunities in the paint.

"You do have to credit their size and everything like that, but we have proven that we can finish in the paint when we're at our best," he added.

However Spoelstra knows he has some work to do on the offensive side.

"Definitely some things where we got flattened out, and they jammed us up in possessions, got us late into possessions. Then sometimes we're forced with those plays, and that can kind of have a different flow and feel to it than if it's just in our typical rhythm of our offense," he said.

But Jimmy Butler, who top scored for the Heat with 28 points, said the key change needs to come from the players not the playbook.

"We didn't play our best tonight. I feel like we just got to come out with more energy and effort, and that's correctible. That's on us as a group. No X's and O's can fix that.

"So come out, dive on the floor, get loose balls, get defensive rebounds and maybe, just maybe, it would have been a different game," he said.

Kyle Lowry said Miami head failed to heed Spoelstra's pre-game warning of what to expect from the Nuggets.

"Coach, he knew how they were going to come out aggressive, and we just didn't — we didn't match the force…we didn't play with the force we needed to play with," he said.

"I think that was their objective, to get in the paint, get inside and use their size and physicality. And that's what they did," he added.

Nikola Jokic and Jamal Murray both had triple doubles for Denver and Caleb Martin said despite their pair's quality, Miami had to be self-critical.

"They are two great players. They obviously had triple-doubles and they can get it done, whether that's passing, playmaking, shotmaking, whatever it is. They are one of the best duos in the league.

"But I don't think that we did enough, as much as we are capable of doing, and making it tough on those guys, kind of like we did in game two. Just find ways in adjusting to the fact they are getting to their spots," he added.

"We just have to have a better approach mentally," Martin said. "Whenever their shots are falling, we can't let that trickle into our offense. Make sure we stay with it and put more pressure on those guys."