LOS ANGELES, United States — LeBron James said he will take time to consider his future after the Los Angeles Lakers were swept out of the NBA play-offs by Oklahoma City on Monday in what could turn out to be the final game of his career.

James, 41, delivered a typically defiant performance with 24 points and 12 rebounds but it was not enough to prevent the Lakers from falling 115-110, as the Thunder completed a 4-0 sweep in the Western Conference semi-finals series.

The four-time NBA champion is now out of contract with the Lakers and will head into the off season as a free agent with uncertainty swirling around his future.

Some reports have indicated James is ready to extend with the Lakers for what would be a 24th season in the NBA, while others have suggested that he may consider heading elsewhere or finally decide to retire from the sport.

James gave little away Monday when quizzed about his plans following a loss in Los Angeles in front of a galaxy of courtside Hollywood stars including Leonardo DiCaprio, Sean Penn and Eddie Murphy.

“I don’t know what the future holds for me,” James said.

“Obviously as it stands right now, tonight, I’ve got a lot of time. I’ll go back and recalibrate with my family and talk with them, and spend some time with them, and then when the time comes, obviously you guys will know what I decide to do.”

James said whether he continues could hinge on whether he felt committed to the grind of playing at the highest level.

“I think for me, it’s about the process — you know, if I can commit to still being in love with the process of showing up to the arena five-and-a-half hours before a game to start preparing.”

Whatever James decides, the veteran superstar feels that he has nothing left to prove after a career that has included a plethora of milestones and records that may never be broken.

“There’s nothing I need to show in this league,” James said.

“I’ve done it all, I’ve seen it all. So you know, just trying to compete and trying to win championships, I think that’s a motivating factor.”

While James contemplates his future, the reigning NBA champions Oklahoma City are looking ahead to a Western Conference finals showdown with either the San Antonio Spurs or Minnesota Timberwolves for a place in the NBA finals.

The Spurs and Timberwolves are tied at 2-2 in their best-of-seven semi-final series.

The Thunder will fancy their chances of advancing after wrapping up an impressive sweep of the Lakers, having also already swept Phoenix in the first round.

Shai Gilgeous-Alexander led the Thunder scorers with 35 points.

In the Eastern Conference semi-finals, Donovan Mitchell went on a record-tying second-half scoring spree as the Cleveland Cavaliers bagged a series-leveling 112-103 victory over the Detroit Pistons.

Mitchell erupted for 39 points in the second half before finishing with 43 points, five rebounds and two assists.

James Harden added 24 points as the Cavs knotted the best-of-seven series at 2-2 in front of a packed Rocket Arena in Cleveland.

It was the third consecutive game where Mitchell had scored 30 points or more, a run of form that has helped Cleveland climb out of a 0-2 hole to square the series.

Mitchell’s 39-point display in the second half also tied the NBA record for most points in a single half of a postseason game, set by Golden State’s Eric Floyd in 1987.

Mitchell said he had apologised to his teammates at the break after a lackluster first-half performance.

“I was trying to set the tone on offence, and I didn’t do that in the first half. I came in at half-time and told my guys, ‘It’s on me’,” Mitchell said. “I tried to make a statement in the second half.”

Detroit had looked ready to take a 3-1 advantage in the early exchanges, battling into a 56-52 lead at the half.

But seven-time NBA All-Star Mitchell took over with a virtuoso third-quarter performance, scoring 21 points in the third as Cleveland launched a jaw-dropping 25-0 run to turn the game on its head, moving into a 75-58 lead that would prove decisive.

The series heads back to Detroit for game five on Wednesday.