WASHINGTON — (CNN) As Republicans prepared to kick off their national convention in Ohio on Monday, the state’s governor was feeling the heat from the party’s presidential nominee.

Ohio Gov. John Kasich will not attend the Republican National Convention in Cleveland this week, and Donald Trump’s campaign manager Paul Manafort think that’s a shame.

“He’s hurting his state. He’s embarrassing his state, frankly,” Manafort said Monday on MSNBC’s “Morning Joe.”

The comments, made on the cable channel’s on-site set in Cleveland, drew groans from some members of the live audience.

Kasich, one of Trump’s rivals for the GOP presidential nomination, is among several prominent Republicans who will be absent at the RNC this week.

Former Presidents George H.W. Bush and George W. Bush are skipping the affair, as are the party’s last two White House nominees, Sen. John McCain and Mitt Romney.

Manafort said that most of the Republicans who are missing the convention “are people who have been part of the past.”

Allies of Kasich defended the governor shortly after the interview.

“Manafort still has a lot to learn about Ohio politics,” tweeted the state’s GOP chair Matt Borges, who supported Kasich during the primaries. “Doesn’t know what he’s talking about. Hope he can do better.”

John Weaver, a chief strategist to Kasich’s presidential campaign, took to Twitter to tout the the governor’s “record approval ratings,” as well his “principle/integrity.”

“Manafort too long with dictators, can’t recognize values,” Weaver said.