Golden State Warriors forward Harrison Barnes has admitted that his side altered their approach to defending LeBron James following their defeat in game three of the NBA Finals.

James scored 40 points to guide the Cleveland Cavaliers to a 96-91 victory over the Warriors at Quicken Loans Arena to give his side a 2-1 lead in the series.

Barnes has revealed that his side watched the film of their defeat, and drastically changed their methods against James in game four to restrict him to just 20 points as the Warriors tied the series with a 103-82 win.

"We watched game three. We saw how effective he was. We saw how he was doing whatever he wanted and we weren't really forcing him to do anything," Barnes told the Northeast Ohio Media Group.

"We were just responding to how he was playing. With LeBron that's one thing, but we definitely came in with the mindset that he has to work. We have to make him play-make.

"If he's going to hit shots, they're not just going to be wide-open shots like he did last game. Every shot is going to have to be contested."

Game five of the series takes place at Oracle Arena later today.