NBA great Steve Nash backed LeBron James to "elevate" the Los Angeles Lakers, but believes it is too soon for the team to contend for the championship.

James, 33, joined the Lakers in July and begins his first campaign with LA against the Portland Trail Blazers on Thursday.

Nash, a former Laker, believes three-time NBA champion and four-time MVP James will lift the team to another level.

"I think it's great for the league, Los Angeles is the most famous franchise in the world," he told a news conference.

"So for LeBron to go there it's going to bring a lot of excitement and a lot of anticipation.

"The Lakers will be very good again, LeBron will elevate the franchise, and I think it's a very exciting time."

While James will help the Lakers improve, Nash said two-time defending champions the Golden State Warriors were still favourites for the title.

However, Nash believes exciting times are ahead for the Lakers.

"I think Golden State's still the favourite. The Lakers will be much better, they have four really good young players," he said.

"But they are 21 years old, I think you need to give them time to develop. It might be a little early for them to compete for the championship this year.

"Next summer they will be a year older. So the Lakers have the exciting time coming up."