President Trump fired back at incoming senator Mitt Romney (R-Utah) on Wednesday, urging him to be a “team player” hours after the publication of a scathing op-ed in which Romney said Trump has not risen to the job.

Romney also drew flak from Ronna McDaniel, the chairwoman of the Republican National Committee — and Romney’s niece — as well as from Sen. Rand Paul (R-Ky.).

“Would much prefer that Mitt focus on Border Security and so many other things where he can be helpful,” Trump said in a tweet. “I won big, and he didn’t. He should be happy for all Republicans. Be a TEAM player & WIN!”

Trump questioned whether Romney, who lost the 2012 presidential election, would seek to play a similar role as the retiring Sen. Jeff Flake (Ariz.), among the few GOP lawmakers who have frequently criticized Trump’s actions.

“Question will be, is he a Flake?” Trump said of Romney. “I hope not.”

Trump voiced some of the same sentiments about Romney during a Cabinet meeting later Wednesday, telling reporters that the former Massachusetts governor could have defeated then-President Barack Obama in 2012 if he had fought him as hard as he was fighting Trump.

In a tweet on Wednesday, McDaniel called her uncle’s op-ed “disappointing and unproductive.”

“POTUS is attacked and obstructed by the [mainstream] media and Democrats 24/7,” she said. “For an incoming Republican freshman senator to attack @realDonaldTrump as their first act feeds into what the Democrats and media want and is disappointing and unproductive.”

Until last year, McDaniel had billed herself professionally as Ronna Romney McDaniel. But the former chairwoman of the Michigan GOP dropped her maiden name from most official RNC communications after a request by Trump.

Later Wednesday morning, Paul also weighed in — on Twitter and in a conference call with reporters.

“I think this is bad for the Republican Party and really bad for any kind of ability to work together in the Senate to get things done,” he said, noting that when he has critiqued the president, he has done so respectfully. “My suggestion would be — let’s keep this more about issues and less about name-calling.”

Romney’s op-ed was published in advance of his swearing-in Thursday as Utah’s junior senator.

In the piece, published online Tuesday night by The Washington Post, Romney said Trump’s “most glaring” shortfall has been in shaping the character of the nation.

Romney said he would support Trump policies with which he agrees, but he also pledged to speak out “against significant statements or actions that are divisive, racist, sexist, anti-immigrant, dishonest or destructive to democratic institutions.”

“After he became the nominee, I hoped his campaign would refrain from resentment and name-calling. It did not,” Romney wrote. “When he won the election, I hoped he would rise to the occasion. His early appointments . . . were encouraging. But, on balance, his conduct over the past two years, particularly his actions this month, is evidence that the president has not risen to the mantle of the office.”

In 2016, Romney was a prominent “Never Trumper,” calling his fellow Republican a “phony, a fraud.”

He adopted a more nuanced view as a candidate for Senate last year, speaking favorably of Trump’s actions on taxes and judicial appointments, among others, but saying he did not consider the president a role model for his grandchildren.

Despite Romney’s harsh criticism of Trump during the 2016 election cycle, Trump considered him for secretary of state but passed him over for Rex Tillerson.

And in February, Trump threw his support behind Romney’s Senate bid, writing on Twitter that he would be a “worthy successor” to retiring Sen. Orrin G. Hatch (R-Utah), whom Trump had urged to run for another term.

Trump allies had already taken aim at Romney before the president’s tweets on Wednesday morning.

“The truth is @MittRomney lacked the ability to save this nation,” Trump’s 2020 campaign manager, Brad Parscale, wrote on Twitter on Tuesday night, adding that “@realDonaldTrump has saved it.” Parscale suggested that Romney’s op-ed was motivated by jealousy.

During an appearance on Fox News early Wednesday, David Bossie, a senior Trump campaign aide in 2016, said he feared that Romney was positioning himself to be a potent Trump critic in the Senate.

Bossie cited other Republican senators who have spoken out against Trump — Flake, Bob Corker (Tenn.) and the late John McCain (Ariz.) — and said Romney has the potential to play those roles “all in one guy.”

Felicia Sonmez contributed to this report.