There are a number of reasons that will have led to Steve Gibson calling time on the 38-year-old’s tenure at the club after just 197 days - the shortest managerial reign in the club’s history.
However, there is one stat that best summarises why Monk now finds himself out of work, after taking charge of 23 league games, Boro won just 10 under the former Swansea and Leeds boss.
On paper, it looks harsh. The club had just recorded a hard-fought victory over Sheffield Wednesday which has left the club just three points away from the play-off places with home games against Bolton Wanderers and Aston Villa to come.
But ask any Boro fan that has watched the club this season and they’ll understand Steve Gibson’s decision, even if they believe that Monk should have been afforded more time.
Boro have never looked like a side that deserved to challenging at the top end of the Championship and even during Monk’s best period as boss - a three game winning streak over Reading, Hull and Sunderland - they were far from convincing.
In fact, in all of Boro’s games this season, fans have never really walked away from the ground feeling 100% confident that the side they were watching were going to mount a promotion push. There was always an element of doubt somewhere in the display.
Whether that was the lack of pace in the final third, arguably the most creative player at the club being consistently left out of the matchday squad, constant alterations to the formation and personnel or - the most common one - defensive errors to the point where it felt like Boro would concede a goal a game through an error at the back.
Boro’s back four has gone from the sturdy and solid red wall under Aitor Karanka to a self-imploding quintet that became the club’s obvious weakness.
He’ll also be criticised for his signings. Of the ten that came through the Rockcliffe door this summer, only really Cyrus Christie and Darren Randolph have consistently impressed from the off while Britt Assombalonga has already scored 11 goals in the Championship this season.
Jonny Howson has improved in recent months and opened his account against Wednesday, but the other have flattered to deceive.
Connor Roberts, Lewis Baker, Marvin Johnson and Ryan Shotton have largely found themselves out of the fold. Martin Braithwaite has been frustratingly inconsistent and Ashley Fletcher has done very little to justify his hefty price tag.
And then there’s the freezing out of personnel. Stewart Downing, Daniel Ayala, Patrick Bamford, Grant Leadbitter and more recently Adam Clayton have found themselves out of the first-team fold with all but Clayton being brought back in after poor displays, not exactly a trait that shows a strong grasp of the playing staff.
Ultimately, Garry Monk’s sacking has been inevitable. His team has looked poor since day one with no immediate signs of improvement, he had a poor to near non-existent relationship with the fans - which counts for a lot in the chairman’s decision-making and he looked like he struggled with the pressure of being pre-season promotion favourites.
Craig Liddle has taken over the first team until the club find a replacement and he already has one major - and slightly sad - advantage in his favour, he’s not Garry Monk. Some fans have wanted Monk gone for some time so seeing someone - anyone - else in the dug out on Boxing Day will be a relief.
The last six months have been hopelessly frustrating and desperately disappointing, but with the manager gone games coming thick and fast, it's time to move on and support the side under his successor.