The Northern Irishman was pressed further on the subject after Rahm last week decided to withdraw his name from the new tech-infused golf league, TGL, which is being run by both McIlroy and Tiger Woods.
As a result of bowing out of the TGL, which starts on January 9, there has been wild speculation Rahm will be leaving the PGA Tour to join LIV Golf.
The TGL is not only the brainchild of both Woods and McIlroy, but it also backed by the PGA Tour.
TGL is a new team-based league with 24 players split across six teams of four.
The new league will see them come down hard on slow play.
But McIlroy admits he would be "very, very surprised" were Rahm to accept a giant cheque to join the Saudi-bankrolled league.
Rahm was reportedly offered in the region of $300m to join LIV Golf last season but the two-time major champion turned it down.
McIlroy is confident Rahm will not be tempted by another lucrative offer in 2024.
According to CBS Sports' Rick Gehman, McIlroy said on November 6:
Rahm's TGL U-turn was down to not being able to fully commit to the new league based in Palm Beach Gardens.
"I am sad to confirm that I will not be participating in the first TGL season," said Rahm last week.
"While I still think it's a great opportunity, right now it would require a level of commitment that I can't offer.
"Best of luck to everyone involved and may the best team win!"
McIlroy also bashed LIV Golf during his TGL press conference.
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