Thomas Tuchel was overperforming at Paris Saint-Germain this season and did not deserve to be sacked, according to his assistant Zsolt Low.
PSG finally confirmed Tuchel's dismissal on Tuesday after days of speculation, bringing an end to his two and a half year stay at the Parc des Princes.
The German coach won back-to-back Ligue 1 titles in his two full campaigns and also won the Coupe de France, Coupe de la Ligue and two Trophee des Champions.
Tuchel also guided PSG to a maiden Champions League final in 2019-20, where they were beaten 1-0 by Bayern Munich.
But he endured a fractious relationship with sporting director Leonardo after publicly calling out the club's transfer chief over a lack of spending heading into this season.
Not helped by a number of injury issues and a lack of pre-season, PSG lost four and drew two of their opening 17 Ligue 1 matches and entered the mid-season break down in third.
However, they beat Strasbourg 4-0 in what proved to be Tuchel's last match and are just a point behind top two sides Lyon and Lille, having also advanced from a tricky Champions League group and into the last 16.
Low has outlined the details behind Tuchel's sacking and says the timing of the decision came as a shock.
"We were surprised because on December 23, after winning a match 4-0 against Strasbourg, Leonardo brought us together to say that the club was no longer counting on Thomas for the future," he told Hungarian outlet Nemzeti Sport.
"After facing considerable difficulties in 2020, after achieving historic success with PSG, after going through the group stage of the Champions League, and with the team in full swing in the league, it made the decision very difficult to understand.
"And the fact that we were impacted by numerous injuries throughout the season, and had to come up against COVID-19. I think that it was a great professional success to finish the year the way we did. We overperformed, that is the truth."
Tuchel appeared to criticise PSG in an interview published on the day of the Strasbourg victory, in which he also admitted managing the club was more like being a "politician".
Although surprised at the timing of the sacking, Low concedes the tense relationship between Tuchel and Leonardo meant something eventually had to give.
"We were shocked," he said. "The summer window did not go as we wanted, the main players who left after the Champions League run were not correctly replaced.
"That created tensions between certain board members and the staff, as well as with the sporting director who was espousing management principles that were different to that of the coach.
"I don't want to delve into the details. They had different ideas in a number of domains, and the difference in viewpoint accrued over time. This led to Leonardo deciding to create a future with a different staff.
"To be honest this situation could not have lasted. It was better to stop now, nearly at the summit, to say goodbye with a great majority of wonderful memories. Not to have followed Thomas would have gone against my values."
Low, who has previously worked as assistant boss at Salzburg and RB Leipzig, added: "Before, I had the opportunity to take the place of managers at Salzburg and Leipzig, and I did not take those opportunities.
"When I fight alongside someone, it is for better or worse. The professional relationship between Thomas and I is extremely tight, he keeps his word, he counts on me, that is why I feel part of the successes.
"And the failures too. I arrived at PSG upon his call two and a half years ago, I was alongside him at all times."
PSG announced Mauricio Pochettino as Tuchel's successor on Saturday, with his first game in charge away at Saint-Etienne on Wednesday.