MIAMI » The San Antonio Spurs left Miami last June looking so human, Tim Duncan nearly in tears talking about how close they were to another championship.

They don’t look human now. They look like a machine.

Up 3-1 and shooting the ball at a level never seen in the NBA Finals, the Spurs headed home with a chance to wrap things up on Sunday night in Game 5.

The Miami Heat, who were able to deny the Spurs last year, have two days to figure out what can possibly be done to do it again.

“They’re a high-oil machine and they move the ball extremely well,” LeBron James said. “They put you in so many difficult positions. If you’re not right on time, right on target, they’re going to make you pay for it.”

The Spurs won by 19 and 21 in the two games in Miami and are shooting 54.2 percent in the series. The NBA Finals record for a series of any length is 52.7 percent.

No team has overcome a 3-1 deficit in the Finals, and the Heat were so thoroughly manhandled in Miami that the only reason to think they could be the first is what they did in the past.

Duncan said the memory of last season’s loss — the pain that’s driven the Spurs through this entire season — would “definitely come up” before Sunday.

“As I said, we know the caliber team they are, and we have a lot of respect for what they’re able to do,” Duncan said. “They’re able to throw it another gear and they’re going to do just that. They don’t want this to be done.”

Duncan probably meant “done” as in the series. Of course, it could also mean the era.

Two off days were sure to be filled by talk of the Heat’s uncertain future, with James, Dwyane Wade and Chris Bosh all eligible for free agency. Might such a one-sided beating convince James he had to leave to find a better roster elsewhere? Make him more resolute in his desire to stay and get the Heat back on top?

The two-time champions have more urgent concerns now. 

“Did we expect to come here and lose two the way we did at home? No way,” Wade said. “But we also expect to go to San Antonio and put up a better effort and try to come out with another win. So we’ll get away from it (Friday), but we’ll still think about what we need to do to try to get another win to keep the series alive.”

James simply acknowledged the obvious, that the Spurs were the better team, when they swept his Cleveland Cavaliers in 2007 for the last of their four NBA championships. But he wasn’t supposed to be on the wrong side of the talent differential once he bolted for Miami, where the Heat would build a Big Three for this decade that would rival what San Antonio’s did last decade.

But the Spurs go so far beyond Duncan, Tony Parker and Manu Ginobili now. There’s Kawhi Leonard, who followed his career-high, 29-point night in Game 3 with 20 points and 14 rebounds Thursday and has done no worse than battled James to a draw over the last two games.

Or Boris Diaw, who wasn’t even in the starting lineup until Game 3 and had eight points, nine rebounds and nine assists in Game 4, serving as one of the catalysts for the Spurs’ mesmerizing ball movement.

Individual players get hot all the time. The Spurs are on a team-wide hot streak.

“I just think we’re playing Spurs basketball,” Parker said. “We’re just moving the ball and we’re just playing the way we’ve been playing all season. We’d like to do a ‘good to great,’ the extra pass, and we preach that, and right now we’re clicking.”

It gets a little harder to keep that going when trying for that fourth win, the one the Spurs couldn’t quite get last year, when even the real freewheeling teams tend to tighten up a bit.

“I mean, every closeout game is very difficult, for all the obvious reasons,” Spurs coach Gregg Popovich said.

Especially if James delivers as so often when the Heat faced elimination, from his 45-point game in Boston in the 2012 Eastern Conference finals, to a triple-double against the Spurs in Game 6 last year, followed by 37 points in Game 7.

He may need to deliver something similar, or a championship reign could be over sooner than expected. 

Brian Mahoney Associated Press