CLEVELAND — LeBron James' ambidexterity makes him special, perhaps the most skilled basketball player on the planet.

James can drive, dribble and create with either hand. It's not widely known that James writes with his left. He never shoots free throws that way.

He did Tuesday.

Bothered by a puzzling injury that numbs his elbow, James curiously launched and missed a free throw left-handed in the closing seconds of Cleveland's 96-94 playoff win over Chicago, adding some unexpected late-night drama to the Cavaliers advancing to a second-round matchup against Boston.

James revealed afterward that the elbow has been troubling him for weeks. He underwent treatment Wednesday and is expected to have further testing done before Saturday's Game 1.

X-rays and an MRI taken on Monday showed no obvious structural damage, but clearly something is wrong with James' elbow, which he has covered recently with a padded, protective sleeve.

"I don't know, honestly, what's going on with it," James said after finishing one assist shy of a triple-double in Game 5. "I've done tests to try and figure this thing out, but it almost feels like you hit your funny bone and it kind of numbs up for a little bit.

"It bothers me more because I don't actually know what it is. We'll figure it out. I've never had a problem with my elbow before."

A Cavs spokesman said the team will provide a medical update after James is evaluated. The team did not practice on Wednesday, giving the puzzling injury another day's rest.

James said he isn't concerned about the elbow and doesn't think it's serious.

If so, then why did he refuse to discuss his elbow when asked about it before the game?

If it's no big deal, then why did he and the Cavaliers essentially hide the injury for weeks?

And, if it's not serious, then why does it seem to be getting worse?

The Cavs are counting on James to be himself in what promises to be a physical series with Boston. The Celtics, written off as too old and on the decline entering the postseason, look ready to challenge the league's best team after easily dispatching the Miami Heat in five games.

After being outplayed in long stretches by the scrappy Bulls, the Cavaliers have enough to worry about as they prepare for their second series in three years against the Celtics. Throw in James' injury, which flared up in Games 4 and 5 against the Bulls, and there could be cause for some legitimate concern.

Maybe as troubling as James' elbow was his decision to shoot his second free throw — arguably his biggest of the season — lefty with 7.8 seconds to go.

When he stepped to the line, the Cavs were leading 95-92. James then calmly drained his first free-throw attempt, but seconds after the ball went through the net, he began shaking his right arm, hoping to get some feeling back before his second shot.

James briefly looked at Cleveland coach Mike Brown and asked if the Cavs had another timeout. They had one left. But with the Quicken Loans Crowd raging, coach and player failed to communicate.

"I couldn't hear him," Brown said following the game. "Apparently, he wanted to take a timeout to get his elbow stretched or looked at or something like that. I did not pick up on it at that time and so he shot the free throw left-handed."

Poorly. The shot clanged off the right side of the rim, missing so badly some thought he may have been trying to miss intentionally. But James later said he chose to shoot left-handed because his right arm was numb and he felt the Cavs were in control with a four-point lead.

"If I had to make it, I'd have tried it with my right hand," he explained.

It's hard to imagine a player like James, who prides himself on his knowledge of the game, believing a four-point lead was safe. There was still plenty of time for the Bulls to push the ball up the floor, score, foul and extend the game by putting the Cavs at the line.

It didn't work out that way. It could have.

James has a flair for the dramatic. Whether accentuating a dunk with a dance move or overplaying a minor injury, he's always putting on a show. He is, after all, an entertainer.

"I do my job," he said when asked about always drawing the spotlight. "I show up to work and I try to do my job at a high level individually and be the leader I am on and off court. As far as the dramatics, I guess it comes with how I do my job at a high level. Am I apologizing for that? No."