OAKLAND (AFP) - Draymond Green's latest low blow in the National Basketball Association play-offs, a strike to the groin of LeBron James, could deliver a kick in the crotch to the Golden State Warriors' title plans.

Green's status for Monday's fifth game of the NBA Finals was in doubt on Saturday after the 26-year-old Warriors forward hit the Cleveland superstar between the legs with a flailing arm when the two tangled and Green fell to the court late in the fourth quarter of Friday's 108-97 Golden State victory.

"He stepped over me," Green told the league's television network. "There's many routes you can take. Don't step over me like that... I don't care who you are. I'm not going to back down."

James and Green exchanged heated words, with the Cleveland star saying "some of the words that came out of his mouth were a little bit overboard", while Green would only say, "Stuff that's said on the court you will never get from me".

The defending champion Warriors seized a 3-1 lead in the best-of-seven series and could capture the crown on their home court on Monday.

But repeated major fouls by Green could lead to a suspension for striking James if league officials review the play and decide Green committed a flagrant foul.

Green would be banned for Game 5 for accumulated play-off violations, most notably a kick to the groin of Oklahoma City centre Steven Adams, a New Zealander, in the Western Conference Finals.

Referees handed Green a flagrant foul-1 but a league review upgraded the blow to a flagrant foul-2 and fined him US$25,000 (S$34,000). Combined with a first-round flagrant foul, Green faces a suspension if his strike on James is upgraded.

"I don't know what should happen. It's not my call," James said. "That's the league office. They will take a look at it."

Asked if he expected any action from league officials over the play, he said: "No."

Green has averaged 15.0 points, 9.7 rebounds, 5.9 assists, 1.9 blocked shots and 1.6 steals a game for the Warriors in the play-offs.

Also, Green defends James and his absence would make life easier for Cleveland's superstar playmaker, who averages 31.9 points, 10.7 rebounds and 6.6 assists in games when his team are facing elimination.

"My mindset is let's get one," James said, hoping to force a sixth game in Cleveland on Thursday. "We've got to fly home anyway so we might as well play on our home floor again."

James, playing in his sixth consecutive NBA Finals and seventh overall, has won at least one road game in 25 consecutive play-off series, but not in these Finals.

"He's a freight train out there," said Warriors coach Steve Kerr. "No matter what you do he is going to have a huge stat line. He's going to impact the game in 1,000 different ways."

Cavaliers coach Tyronn Lue was unhappy James only had four free-throw attempts.

"He never gets calls," Lue said. "He's one of the guys that attacks the paint every single play. He doesn't get a fair whistle all the time because of his strength and power and guys bounce off him. Those are still fouls and we weren't able to get them. But we've got to play through the officiating."

The Warriors, who won a record 73 regular-season games, must avoid thinking the series is done when they need one more win. But they rallied from 1-3 down to beat Oklahoma City in the Western Conference Finals so that lesson is fresh in their minds.

"This is a great opportunity," Warriors and NBA scoring leader Stephen Curry said. "We need to play with a sense of urgency and aggression."