MIAMI -- As Jimmy Butler walked to the podium following the Miami Heat's 116-99 loss to the Boston Celtics in Game 4 of the Eastern Conference finals Tuesday night, he was singing.

It was Alicia Keys' 2007 song "No One." But the specific verse he closed with was, "Everything's gonna be alright."

While Butler and the 8-seed Heat lamented that they couldn't close out the Celtics and earn their second trip to the NBA Finals in four seasons, there remained an air of confidence within the group that it could go back to Boston for Thursday night's Game 5 and find a way to win one more.

"If anything, it will build momentum for us knowing that we have to play with a lot more energy," Butler said. "We've got to play like our backs are against the wall. But I think all year long, we've been better when we've had to do things the hard way."

Butler scored 29 points while grabbing nine rebounds and dishing out five assists, but he was still frustrated with the way he performed with so much at stake for a Heat squad that came into Game 4 hoping to complete the sweep. The Celtics narrowed the series deficit to 3-1.

Despite the setback, Miami coach Erik Spoelstra said he didn't get the feeling his team might suffer a letdown after failing to finish the series at home and get rested for a Finals matchup against the Denver Nuggets.

"I didn't sense any of that," Spoelstra said. "At some point, this is great competition. You know, sometimes it can get skewed, because, whatever, the 3-0. But we have great respect for Boston, what they are capable of. They are a dynamic offensive team that takes extraordinary efforts and commitment to get the job done. Our guys really want this ...

"A lot of what we've done this year has been the hard way. We've been able to figure out ways to win, even if teams are playing well, if we are not in a perfect flow. And they got us tonight. You have to give them credit for that."

Heat guard Caleb Martin echoed a similar sentiment, acknowledging the bitterness of the loss but remaining positive about what's ahead for Miami.

"It's definitely disappointing," Martin said. "That would have been a perfect world, perfect situation. But as we know and everybody else knows, we don't typically get things the easy way over here. So like I said, this is right up our alley. This is the way it goes for us and guys like us. Again, I think it's only going to prepare us for the long run. This could be good for us."

That is what Butler is hoping, as well. He said he didn't feel the need to say anything to the group as it prepares for a difficult challenge on Thursday against a Celtics team that finally appears to have woken up.

"The only thing I'm going to say is we'll be OK," Butler said. "Let's get back to doing what we've always done to get us to this point: Continually have belief in one another, knowing that we are going to win, and we will. We've just got to play harder.

"There's not too much to say with this group because we already know. So we've just got to go out there and execute."