A shake-up had been signposted as far back as the spring.
It was in early April when Newcastle announced that defender Kieran Trippier would be leaving at the end of his contract.
The 34-year-old was approaching the twilight of his career, but his departure was still keenly felt as an influential figure behind the scenes.
“It was emotional for me, of course, because I loved the club so much and Newcastle gave me so much in return,” the former England international said several months after moving on to Wolves.
“I’ll always follow the club and want them to do well but, as a footballer, sometimes, you have to move on. With the utmost respect, I think it was the right time for both the club and myself.
“As I’ve always said, I wanted to leave in the right manner and show respect to my team-mates, the club and, most importantly, the supporters, who I have a great relationship with.”
Anthony Gordon and Sandro Tonali’s subsequent exits to Barcelona and Tottenham respectively did not necessarily come as a surprise, either, given they enabled Newcastle to comply and reinvest within the game’s financial rules.
No-one internally had countenanced losing talisman Guimaraes, though.
However, having bailed Newcastle out so many times before, even the tireless midfielder dropped to the turf, untied his boots before the physio reached him and glared at the bench to come off during last season’s final-day defeat at Fulham.
If ever an image summed up a bruising domestic campaign as Newcastle finished in 12th place – far below where the hierarchy had projected – and missed out on millions worth of European revenue.
The prospect of Guimaraes signing a new deal was unsurprisingly shot down by a figure involved in his subsequent £75m move to Arsenal a few weeks later.
After losing Alexander Isak to Liverpool against their wishes last summer, Newcastle ended up selling a fourth key player in less than a year.
They also missed out on top targets Victor Munoz and Johan Manzambi, who opted to move to Liverpool and Aston Villa respectively.
Yet those inside the club repeatedly stressed that the window could only be judged once it shut.
“Just because one element doesn’t go the way you want doesn’t mean you abandon the plan,” a senior source said.
“We stayed on target, stayed focused, stayed calm and moved on. We didn’t do a whole lot of mourning or crying when we had a setback.
“We pivoted to what’s next.”