DENVER (AP) — The Miami Heat are searching for inspiration anywhere they can find it, including a tennis great’s record-setting win at the French Open and even their mascot’s quick rebound from a few punches to the face.

Jimmy Butler and the Heat might be down 3-1 in the NBA Finals against the Nuggets heading into Game 5 on Monday night in Denver, but they hardly consider themselves out.

“(Our belief) is at an all-time high,” said Butler, whose team is hoping to avoid watching the Nuggets celebrate their first NBA title. “It always has been all year. It always will be.”

From Day 1, the Heat have demonstrated their scrappiness. At first, it was in scrimmages against each other in training camp and later in earning the No. 8 seed into the postseason through a second chance in the play-in tournament. They knocked out Giannis Antetokounmpo and Milwaukee in the first round, then the New York Knicks, and rebounded in Game 7 in Boston after squandering 3-0 lead in the Eastern Conference finals.

Bottom line: They’re used to doing things the hard way.

“They love the ultimate challenges and the ultimate competition,” Heat coach Erik Spoelstra said. “The narratives are not going to decide it. Whatever the analytics are about 3-1, that ain’t going to decide it. It’s going to be decided between those four lines, whose game can get to whose game and ultimately win at the end. That’s what our guys love.”

A little motivation goes a long way, too. They drew encouragement from Serbian great Novak Djokovic earning his men’s-record 23rd Grand Slam singles championship Sunday with a victory over Casper Ruud.

The Heat are trying to channel the inner belief Djokovic displayed as they face another Serbian standout in Nuggets big man Nikola Jokic.

“(Djokovic) has talked about that mental side of the game,” said Spoelstra, who had no update on the availability of Tyler Herro, the sharpshooting guard sidelined by a hand injury. “We have a very stubborn and defiant group, and I think it’s good to have a little bit of defiance from time-to-time.”

For tenacity, the Heat don’t need to look any farther than their mascot, Burnie, who took two punches from former UFC champion Conor McGregor in a skit that led to the person in the costume seeking medical attention. Burnie could be back on the court, though, should the Heat force a Game 6 in Miami on Thursday.

“That’s the Miami Heat toughness that we’re talking about,” Spoesltra said of the mascot’s return. “He should have been allowed to take the first swing. We won’t reveal who that is, but yeah, he can take a punch and get back up.”

The Nuggets have the Heat down on the canvas, with no desire to let them back up. Still, they realize it won’t be easy.

Closeout games rarely are.

“Obviously, they’ve been doubted the whole year and they made it this far for a reason,” said Nuggets guard/forward Bruce Brown, whose team is 9-1 at home, with the lone blemish in Game 2 against Miami. “It’s going to be crazy. It’s going to be loud. The fans are going to be here probably early. But I can’t wait. I feed off their energy, so hopefully it’s going to be a big night.”

The Nuggets have history on their side. Of the 36 teams that have fallen behind 3-1 in the NBA Finals, the lone one to come back to win the title was the 2016 Cleveland team led by LeBron James against Golden State.

On that Cavaliers squad was Kevin Love, the 34-year-old Heat forward who’s been preaching that anything can happen.

“You really just have to take it one possession at a time,” Love said. “It’s just one possession, one quarter, half-to-half. Just get it done by any means necessary and figure the rest out.”

Butler couldn’t agree more. Just don’t mention moral victories and how much they’ve accomplished.

It’s ring or bust.

“All the odds, 8-seed — nah, none of that matters,” Butler said. “It’s just two really good basketball teams. One has to get one win, and one has to get three. Let’s just hope that the other that has to get three, gets three.”