Facing a tough re-election battle, US President Donald Trump has replaced his campaign manager.
Mr Trump said Bill Stepien, a field director for his 2016 campaign, would take the place of Brad Parscale.
Mr Parscale - who was reportedly blamed by Mr Trump's inner circle for a poorly attended rally in Oklahoma last month - will stay on as senior adviser.
Opinion polls show the president is trailing his Democratic challenger Joe Biden ahead of November's election.
Mr Trump's statement on Facebook on Wednesday evening said: "Brad Parscale, who has been with me for a very long time and has led our tremendous digital and data strategies, will remain in that role, while being a Senior Advisor to the campaign."
In one of his first official acts as campaign manager, Mr Stepien issued a statement on the "state of the race", praising Mr Parscale and pledging to "expose Joe Biden as a hapless tool of the extreme left and contrast his failures with the undeniable successes of President Trump".
"The same media polls that had the world convinced that Hillary Clinton would be elected in 2016 are trying the same trick again in 2020. It won't work."
What happened in Tulsa?
Mr Parscale is said to have found himself sidelined in recent weeks after the president's comeback rally in Tulsa flopped.
Mr Trump's daughter Ivanka Trump and her husband Jared Kushner, both White House advisers, are reported to have blamed him.
Mr Parscale had boasted that more than one million people had registered to attend, but fewer than 6,200 showed up at the arena, the local fire department said.
After the rally, Mr Parscale went on Twitter to blame a blocked security gate, protesters and the media for the disappointing turnout.
There had been concerns about holding the rally during the coronavirus outbreak and those attending had to sign a waiver protecting the Trump campaign from responsibility.
President Trump appeared deflated as he returned to the White House, with his tie undone and his Make America Great Again cap in hand.
Not a good sign
Replacing a campaign manager just over 100 days before an election is not a good sign. That may seem obvious, but to listen to Donald Trump one might get the impression that things are going great.
They are not.
Polls can be inaccurate, but there's no way to spin double-digit deficits - and Brad Parscale suffered the consequences.
Mr Parscale was always an unusual choice to lead Mr Trump's re-election effort, given that he had never run a campaign of any size before. Managing a presidential-level operation is the equivalent of overseeing a massive business venture constructed on the fly - an administrative task that requires organisational acumen, strategic vision and ruthless efficiency.
It's not a job that comes with training wheels.
The Trump 2016 operation was a shoe-string affair - a lean political insurgency that caught lightning in a bottle. This time around, the Trump campaign is a billion-dollar enterprise that, like any undertaking of such size, risks becoming bloated, inefficient and unresponsive without adequate leadership.
Bill Stepien, Mr Parscale's replacement, will bring more political experience to the job. In the end, however, it's the president and his family who call the shots.
New organisation and focus can help, but any chance at political revival starts with Mr Trump himself.
Who is Parscale and who is Bill Stepien?
Brad Parscale is a brash figure, keen on attention.
He was hired by the Trump Organisation back in 2011 as a digital guru and later served as a warm-up act for Mr Trump at rallies.
He was then appointed campaign manager in February 2018 - thought to be the earliest time any incumbent US president has officially declared his re-election campaign.
CBS News reported recently that Mr Parscale did not even vote in the 2016 election, citing his difficulty in obtaining a postal ballot while working at Trump Tower in New York City.
Bill Stepien was parachuted in to help the Trump 2016 campaign at a similar time of gloomy polls.
He brought a lot of experience, working on the election bids of John McCain in 2008 and George W Bush in 2004.
Mr Stepien was also a former aide of New Jersey Governor Chris Christie and his name came up in the so-called Bridgegate scandal that was widely perceived to have scuppered Mr Christie's presidential ambitions.
What does a campaign manager do?
Win elections. Although it's not an easy job to keep. Bill Stepien is Mr Trump's fifth, following Kellyanne Conway, Paul Manafort, Corey Lewandowski and Mr Parscale.
You need to be on top of raising funds - and using them well, particularly in targeted advertising. Getting people out to vote goes without saying.
Mr Stepien is another data and metrics guru, skilled at focusing in on success stories and hammering the message home, so that should help.
Then there is running opinion polls to see how it's going - and Mr Stepien will have to start turning round some troubling numbers.
One of the latest opinion polls, on Wednesday by Quinnipiac University, put Joe Biden 15 points ahead, with leads in key swing states Arizona, Florida, North Carolina, Pennsylvania and Wisconsin. It showed Mr Trump's approval rate sinking to 36%.
At least Mr Stepien appears to understand his boss, saying ahead of the mid-term elections: "The president is a very results-oriented president. He wants seats won."