Four-time major champion Rory McIlroy believes the PGA Tour needs to take a leaf out of the NBA's book and build itself around star athletes.

The 33-year-old Northern Irishman, who has fiercely defended the PGA Tour amid the rise of LIV Golf, said the organisation could look at other professional sports leagues as models to rebuild itself for growth.

The PGA Tour is weighing up format changes like making at least some of the designated events limited-field, no-cut tournaments.

Tiger Woods spoke about the challenges of the PGA Tour's direction on Tuesday ahead of this week's Genesis Invitational in California, with McIlroy weighing in on Wednesday.

"If you look at the NBA's trajectory over the last 20 years, they've built that league around their best players and their stars, not around the 12th guy on the team," McIlroy told reporters.

"But because they've built that league up around the stars, the 12th guy on the team does way better than he used to, so that's sort of the way I've been trying to tell it."

McIlroy insisted that any PGA Tour changes would not "screw" the lower-ranked, bottom-half players who he sensed had concern around format adjustments that could squeeze them out of tournament fields.

"I've had tons of conversations with guys that are worried about what events they're going to play next year and all that," McIlroy said.

"The one thing I said, look, no one's trying to screw the bottom half of the tour here. If anything, we're trying to lift it up.

"The best players should be playing in them because ultimately the PGA Tour needs to be built around the best players because that's what will maximise the value of the product.

"But that doesn't mean that there's not great storylines further down that list, which we're all very cognisant of."

McIlroy can regain his number one ranking at the Genesis Invitational but laughed that status has been passed around "like a hot potato" in recent times, with last week's Phoenix Open winner Scottie Scheffler re-claiming it.

"Yeah, of course I care about it," McIlroy said. "I think it's a really cool thing to be ranked number one in whatever you do, but I think it just goes to show the level of depth and the level of talent that's out here.

"I literally have one average week, it wasn't even a bad week, just an average week, and there's always someone waiting to overtake you or to come and try to take that mantle from you. I think it's a great thing for the game.

"I've got a chance to get it back this week. You know, hopefully it's a bit of a sort of hot potato thing where me, Scottie and Jon [Rahm] sort of pass it around a little bit because it means we're all playing great golf."