Former Texas Gov. Rick Perry, who once called Donald Trump “a cancer on conservatism,” said Friday he would be willing to serve as the presumptive Republican nominee’s vice president.

Perry said he will do whatever he can to help Trump — including joining him on the Republican ticket in November.

“I suspect I’m going to be helping him in a myriad ways — but if it’s the vice presidency, if a cabinet position is where he needs somebody with my experience then I’m not going to go back to Texas and say, ‘Aw shucks sir, I’m gonna go fishing.’ I’m gonna go serve my country,” Perry told CNN backstage at the National Rifle Association’s annual meeting.

Perry told Republican donors Wednesday on a conference call hosted by Great America PAC, a pro-Trump group, that he would help Trump any way he could “within reason” and appeared to make his case for the vice presidency — pointing to his foreign policy and government experience just as he talked up those same qualities as those Trump should look for in selecting a running mate.

Asked Friday whether the vice presidency was “within reason,” Perry was blunt: “Of course it is,” he said.

Perry, who ran against Trump in the GOP presidential primary, has recently emerged as a top Trump surrogate and didn’t shy away from addressing his past forceful criticism of Trump.

“I had strong things to say about him,” Perry acknowledged when asked about his speech last fall in which he described Trump as a “cancer on conservatism.”

But Perry argued Friday that conservatives who are reluctant to support Trump should rally behind the presumptive GOP nominee to at least prevent Hillary Clinton from nominating a liberal justice to replace the late Supreme Court Justice Antonin Scalia.

“The more time I’ve spent with him and discussed the issues, the more comfortable — there are a lot more things we agree on,” Perry said. “I believe Donald Trump would be a great President of the United States and I think we all have the opportunity to reevaluate an individual after you get to know them better and that’s exactly what I’ve done.”

“Mr. Perfect left the building a long time ago,” Perry added.