Donald Trump spoke glowingly of former Texas Gov. Rick Perry's future political prospects when asked about a potential challenge to Sen. Ted Cruz in 2018.

As Trump began to introduce Perry at a private fundraiser on Tuesday, an audience member reportedly asked about a potential Perry Senate bid. Trump then praised Perry at length, according to audio of his answer published by the Lone Star Project, a Democratic-aligned political action committee.

"I'll tell you what, I've been hearing a lot about that and I don't know if he wants to do it, but boy will he do well," Trump can be heard saying. "People love him in Texas and he was one great governor."

Trump continued, "I don't know what he's going to do. If he's got an announcement ... then it will blow Trump away, they'll say Trump was also there, right? Headline."

Perry was a rival and critic of Trump in the 2016 GOP primary, and later supported Cruz, but Perry has since boarded the Trump train. Cruz, Trump's foremost competitor before the businessman won the GOP nomination, has not endorsed Trump and courted controversy for encouraging Republicans to "vote your conscience" in November during a speech at the GOP convention this summer.

Cruz will seek re-election in 2018 and speculation has already begun to swirl that he could face a primary challenge. If a challenger emerges, Trump could be supportive.