Anthony Davis has eased fears about the severity of the back injury that forced him out of the Los Angeles Lakers' Game 4 win over the Portland Trail Blazers.

The Lakers cruised to a 135-115 victory to take a 3-1 lead in the first-round series on Monday, but they were without Davis for most of the second half due to back spasms.

The seven-time All-Star headed to the locker room early in the third quarter - when the Lakers had a huge 91-53 lead - and later watched the rest of the game while standing on the sidelines with an electric stimulation device wrapped around his back.

Davis, who had 18 points in his 18 minutes on the court, does not think it is a major issue, though, as Los Angeles look to seal the series win in Game 5 on Wednesday.

"Back is doing fine. I'll be fine," he told reporters after the game.

LeBron James led the Lakers with 30 points and 10 assists on an emotional night for the franchise, who were remembering the great Kobe Bryant on August 24.

Bryant, who wore the jersey numbers 8 and 24 during a decorated career with the Lakers, was killed in a helicopter crash in January, along with his daughter and seven other people.

James arrived at the game wearing a Bryant Lakers jersey and Davis revealed he has seen a different side to the four-time MVP since the postseason began.

"Obviously we've kicked it up a notch," Davis added.

"His level of focus is definitely increased and the entire team's level of focus has increased. He's very detailed about everything. He's in there with coaches for film sessions, he's talking to me during film sessions.

"He wants to win and I want to win and we know that it's going to take both of us to do it, and the entire team, so we're just continuing to find ways to get better, even after wins like this.

"There's always something we can be better at for Game 5. I'm pretty sure that he's going to have a list of things for me tomorrow and the entire team."