As underachieving members of English football's aristocracy in recent years, United hope the showpiece at Wembley can serve as a long-awaited rebirth.
However, revelling in their role as nouveau riche irritants to the Premier League's established powers, Newcastle believe the final can serve as concrete proof they are now a force to be reckoned with.
United haven't won a major trophy since the 2017 Europa League, a prize they claimed just weeks after beating Southampton in their most recent League Cup final appearance.
As if their longest trophy drought for 40 years wasn't bad enough, United also suffered the indignity of watching bitter rivals Manchester City surpass them as England's preeminent football force.
United, who last won the title in 2013, finished a dismal sixth in the Premier League last term.
But after a decade in the wilderness, they have been revived by Ten Hag since his arrival from Ajax last year.
Crucially, Ten Hag's handling of Cristiano Ronaldo showed he would not be intimidated by player power, bringing an end to the Portugal star's second spell at United.
"He first arrived and the training sessions we had, he demands 'you do it or you're out'. You don't play," United midfielder Bruno Fernandes said.
"Everyone was a little bit like 'If a big player doesn't do what he wants will he pull him apart or not?' And he did that many times, he did it with Cristiano, with Jadon (Sancho), with Marcus (Rashford)."
There is no more tangible sign of Ten Hag's impact than the blistering form of revitalised United forward Rashford, who is battling to be fit for Wembley after suffering an injury in Thursday's Europa League win against Barcelona.
Ten Hag has tried to temper expectations in his first season but he knows victory this weekend would be a meaningful moment for a club climbing out of the doldrums.
"It's a great opportunity to get the silverware. The fans are really waiting for it and so we do everything we can to give them their honour," Ten Hag said.
- 'Rewrite the story' -
Fuelled by the astute management of Eddie Howe and the financial muscle of their Saudi-backed owners, Newcastle are unlikely to be a pushover.
Once regarded as the laughing stock of the Premier League, Newcastle are emerging as a genuine force for the first time since Kevin Keegan's 'entertainers' came close to winning the title in the 1990s.
It is an astonishingly rapid rise for a team who were mired in the relegation zone when Howe was hired soon after the £305 million ($376 million) takeover from unpopular former owner Mike Ashley in late 2021.
Saudi's Public Investment Fund holds an 80 percent stake in the club, but Howe is the public face of Newcastle's renaissance.
Despite a recent dip in form, Newcastle are fifth in the Premier League, just two places behind United.
For this weekend, they are focused on winning the club's first major trophy since the 1969 Inter-Cities Fairs Cup.
Newcastle's last major domestic prize came in 1955 when they lifted the FA Cup.
For such a football-obsessed city to go decades without a trophy has been cruel punishment for the long-suffering 'Toon Army', who will be watching Newcastle's first domestic final appearance since losing to United in the 1999 FA Cup.
Fittingly for a final offering potential catharsis to both clubs, Newcastle are set to start much-maligned goalkeeper Loris Karius.
Nick Pope's suspension has given Karius a chance at redemption in his first competitive match in almost two years.
Karius is best known for his costly howlers in Liverpool's 2018 Champions League final defeat against Real Madrid.
"It would be a magnificent chance for him to rewrite the story of his career," Howe said.
"That's the beauty of football. We never know what is going to happen. This unpredictability is what makes it such an amazing thing to watch."
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