This is a club that spent some £100 million ($132m) in preparation for their last Premier League campaign, money frittered away as Fulham were relegated at the end of the 2018-19 season having conceded 81 goals.
There was a divided dressing room; the presence of expensive signings who failed to make an impact upsetting those who had gained promotion the previous campaign.
Heads dropped all around Craven Cottage. So deep was the hurt that a double relegation similar to that of Sunderland was not out of the question.
Jean-Michael Seri, Andre-Frank Zambo Anguissa, Floyd Ayite, Andre Schurrle, Luciano Vietto and Sergio Rico were among those who departed last summer, with those that were up for the fight remaining to take on the 46-game Championship marathon.
"I realised the squad was fragile, the football club was fragile and we had these separate bands," Parker had said ahead of kick-off at Wembley.
"At the forefront of my mind was trying to bring the club back together a little bit and try to create an environment and culture.
"In all successful clubs and businesses, it comes from a core foundation, when everything runs in the right way and everyone is on the same page. The club was very disjointed. We were in a bad spell.
"It has been a rocky road because you can’t just have a magic wand and go from real disbelief, a real weak mentality and disconnection and within two months be fighting to win."
Top goalscorer Aleksandar Mitrovic, captain Tom Cairney, and full-backs Joe Bryan and Cyrus Christie were standouts all season long in returning Fulham to the top table of English football.
New signings Michael Hector, Bobby Decordova-Reid, Harrison Reed, Ivan Cavaleiro and Anthony Knockaert all came in - with the latter two having experienced promotion from the Championship previously with Wolves and Brighton.
"This was a team that 15 months ago lost most weeks," Parker said. “Everyone could see that from the outside and judge that. What people did not see and did not understand was a deep-rooted issue at a club that had some wounds and issues.
"We have tried to change the mentality. I am proud because I see a team that has transformed. Some clear errors were made [when Fulham were promoted] last time and we will learn from that."
Brentford were the fairy-tale story ahead of kick-off. One of the Championship's smallest clubs tried to return to the top flight for the first time since 1947 in the season they said goodbye to their 114-year-old stadium Griffin Park.
But Fulham shut out a 58-goal front three of Ollie Watkins, Said Benrahma and Bryan Mbeumo. At the other end, an unlikely hero in left-back Bryan stepped forward, striking twice in extra-time to deliver promotion.
The first - a 36-yard free-kick from a wide angle - exploited David Raya's position with Parker telling his full-back to shoot seconds earlier having identified the goalkeeper's weak point.
"We had done our due diligence on their keeper and he has a very aggressive starting position from free-kicks," Parker said.
"I called Joe over but I did not want to let on to Brentford’s bench and players, so we tried to bluff it a bit. I said to Joe: 'Listen, I want you to go for it. I want you to commit to it.'"
The second goal completed the task before Brentford struck late on.
For Parker, there were tears of joy and he cried in the arms of his talismanic No.9 Mitrovic after what has been an exhausting journey.
He is now delivering the standards in management that he did in his playing career.
Parker has been a polite and big-thinking leader, overturning every stone to get to the Premier League. He deserves to be placed alongside Frank Lampard and Steven Gerrard in the category of talented and emerging English managers.
Fulham now have to prove they have learned from their mistakes last time having achieved this £130m ($171m) promotion bonanza, and aim for a more permanent place in the top flight.