The friend then said later in the day that he spoke to Priebus and has an "open mind."
Christopher Ruddy, CEO of Newsmax Media, told CNN's Brian Stelter on "Reliable Sources" he thinks "there's a lot of weakness coming out of the chief of staff."
"I think Reince Priebus, good guy, well-intentioned, but he clearly doesn't know how the federal agencies work," said Ruddy. "He doesn't have a real good system. He doesn't know how the communications flow."
It was a strikingly frank public assessment of one of Trump's top staffers by a close friend, but it's unclear whether Trump shares it.
Ruddy later tweeted: "Reince just briefed me on new WH plans. Impressive! CNN today my personal view. Told him I have 'open mind' based on his results."
Ruddy's Newsmax Media is a Florida-based, conservative-leaning news outlet whose properties include a magazine and a cable TV channel.
He was on CNN Sunday morning to talk about media treatment of Trump, but he spent a portion of his time knocking Priebus.
"I think the President is not getting the back-up he needs in the operation of the White House. Sometimes the push-back that he needs, which you would have with a stronger White House counsel. That you would have with a stronger White House chief of staff," Ruddy said.
The White House did not immediately respond to a request for comment.
Ruddy had spent Friday night with Trump at his Mar-a-Lago estate in Florida, tweeting: "@POTUS super impressed by (Japanese Prime Minister Shinzo) Abe. Our topics: Media, Haberman, NY Times, 'Fake News', Nordstrom's, China, Putin, Nukes, more."
Trump spent his weekend at Mar-a-Lago with Abe as his guest.
Ruddy told The Washington Post in an interview
later Sunday he wouldn't reveal where Trump stands because their Friday night conversation was private. But he did elaborate on his own feeling that while Trump could have had some easy wins his first week in office, there have instead been some stumbles.
"A lot of people have been saying, 'Look, Donald has some problems,' and I think he realizes that he's got to make some changes going forward," Ruddy told The Post, blaming Priebus for the problematic rollout of Trump's immigration ban, which has now been stalled by the courts.
The sniping within Trump's inner circle is not unusual.
During the campaign and the early stages of his presidency, Trump has been known for doing little to quell staff infighting -- often pitting aides against each other to see how ideas and approaches play out.
Reports early of the Trump White House's functioning have focused on two factions: One led by Priebus and former Republican National Committee colleagues, including deputy chief of staff Kate Walsh and press secretary Sean Spicer; the other led by chief strategist Steve Bannon and policy adviser Stephen Miller. Kellyanne Conway, Trump's campaign manager, also plays a role as counselor, as does son-in-law Jared Kushner, a senior adviser.
Trump and Priebus were not immediate allies. Priebus as RNC chairman pushed Republican presidential candidates to sign loyalty pledges, guaranteeing they'd back the primary winner, in part out of concern over Trump. Trump has also said Priebus pushed him to exit the race after the "Access Hollywood" video surfaced. But since then Trump has said Priebus turned out to be a "star," and tapped him for a chief of staff role that puts him atop the West Wing's pecking order and in charge of its operations.