CLEVELAND — It happened so fast.

One minute, the NBA Finals were a drama-free sweep, with the Warriors simply superior to LeBron James’ undermanned Cavaliers team that had just fallen in Game 4 on Friday at Quicken Loans Arena.

The next minute, as reporters prepared to pepper James about his forthcoming free agency, a massive and mysterious subplot emerged.

James, as first reported by USA TODAY Sports, had suffered a hand injury after the Cavs’ overtime loss in Game 1 on May 31. In a fit of frustration, he took his wrath out on a whiteboard in the visitors’ locker room that night at Oracle Arena. Just like that, with James suffering a deep bone bruise on his right (shooting) hand that he feared was a fracture, this already-daunting challenge became ‘‘Mission: Impossible.’’

‘‘I pretty much played the last three games with a broken hand,’’ James said as he sat with a soft cast on his right hand.

The timing of the revelation led to all sorts of speculation, with fans and media members suspecting the leak was coming from James’ camp as a way to provide cover for his latest Finals loss. But word of James’ injury didn’t originate from his camp, and it makes little sense he would be eager to reveal this lapse in judgment.

Yet when James appeared on the postgame podium with his cast, it only fueled the fire of faulty assumptions. The assertion from James’ side, however, is he only wore the cast because he already had been told the news was out.

According to a person with knowledge of the situation, James wouldn’t have worn the cast if his injury already had not been reported. His teammates and coaches knew what had happened, and it’s a wonder it didn’t come out sooner.

James didn’t go into detail about how much the injury affected his play. He explained the human side of it all, how the comedy of errors in the series opener put him over the edge.

There was George Hill’s missed free throw that would have won the game in regulation, J.R. Smith’s brain freeze when he lost track of the score, the timeout that Cavs coach Tyronn Lue left unused and the many calls the Cavs didn’t agree with. And then there was James, taking that razor-thin margin of error between the teams and making it even smaller with one painful swing.

‘‘I had emotions on [how] the game was taken away from us; I had emotions of [how] you just don’t get an opportunity like this on the road versus Golden State to be able to get a Game 1,’’ he said.

A video of him exchanging elaborate handshakes with his sons immediately after Game 4 had some fans crying foul, as did the replay of his two-handed, off-the-backboard dunk in Game 3 that he finished with such force.

But then ESPN published side-by-side photos comparing his swollen right hand to his healthy left, and it seemed clear he was hurting. James’ hand was so swollen after Game 1 that the initial MRI exam didn’t reveal clear results. A second was required later to determine there were no fractures.

As for the question of how much James’ injury affected the Finals, it’s impossible to tell. Only James knows for sure.

Considering how dominant he was in Game 1, scoring a playoff career-high 51 points (on 59.3 percent shooting) to go with eight assists and eight rebounds, the gap between the before-and-after numbers is stark enough to make this the latest what-if scenario.

In the final three games, James averaged 28.3 points (on 49.2 percent shooting), 10.7 assists and 8.7 rebounds. In between, the Warriors’ best option for defending him, Andre Iguodala, returned from an injured left leg after missing the first two games.

‘‘I let the emotions get the best of me,’’ James said.

As for whether he might have gotten the best of the Warriors if he never had taken that swing, we’ll never know.