As the Miami Heat get set for the Eastern Conference finals against the Boston Celtics, Jimmy Butler and his teammates do so with the same air of quiet confidence they've carried with them since the NBA restarted its season.

The All-Star swingman brushed off the idea that the fifth-seeded Heat should feel like an underdog against the third-seeded Celtics when the series begins Tuesday night.

"We don't really use 'underdog,'" Butler said after Saturday's practice. "We may say that we have a chip on our shoulder, but I don't think that we're the underdog. I think that we're a really good team. We play together. Everybody knows their role. We just compete.

"... I think we're supposed to be here. That's how we think of it. To me, to us, that's all that matters. We're not underdogs. We're competitors."

The Heat have become the story of the bubble after sweeping the fourth-seeded Indiana Pacers in the first round and beating the top-seeded Milwaukee Bucks in five games in the conference semifinals.

The approach taken by Butler and his teammates is paying dividends on the postseason stage as they continue to believe in the culture that longtime Heat president Pat Riley and coach Erik Spoelstra have created over the years.

Butler is buoyed by the work ethic that his teammates and coaches have displayed since he signed with the organization last summer. That poise -- and the work behind the scenes -- is why he's convinced the group will rise to the occasion against a talented Celtics group that just knocked off the defending NBA champion Toronto Raptors in seven games.

"We all think that we're the better team," Butler said. "We all think that we're supposed to be here. And that's the way that I think. ... I love the way that our guys think like that as well, because I think confidence and your mental [approach] is the majority of this thing.

"We always talk about beating the bubble, I think we've done a great job of doing that thus far. So going into these games, it's about us. We're in control of our destiny right now."

The Heat and Celtics met in intense playoff series in 2011 and 2012, when LeBron James, Dwyane Wade and Chris Bosh were leading Miami to the NBA Finals. Butler tried to downplay the rivalry between the teams over the years, which included some verbal jabs between Riley and Celtics general manager Danny Ainge.

"I think those teams were way better than the teams we got now," Butler said. "You talk about having D-Wade and Bron and C-Bosh -- those are some hellified players. ... Looking at it now, I think it's fun to say it's a rivalry and it's the ultimate level of competing. You talk about the back- and-forth with Coach Pat, it doesn't surprise me any. I love it. That's why we are who we are. Because the head of our snake, him, he's like us."

As far as the current series, Spoelstra doesn't think the previous meetings this season -- all three were the second night of back-to-back games for the Heat -- will factor into the preparation.

"You almost can't draw anything from those games, because there are so many different moving parts that are different than they are now," Spoelstra said. "Of course, both coaching staffs will continue to dive into all that. But something that really stuck out to me, when you start diving into the film, somebody's always been missing. Multiple people in each of those games.

"At the end of the day, we're a totally different team, certainly than the first time we played them in December. And they're a much different team. That's what you expect out of high-quality, high-level teams."