Jose Mourinho has aimed a subtle dig at Manchester United manager Ole Gunnar Solskjaer, claiming "nice guys" end up being controlled by the club's senior officials.
The Portuguese coach was axed by United in December, after overseeing the club's worst start to a top-flight season in 28 years.
Solskjaer was drafted in as his replacement on an interim basis, embarking on a run of 14 wins from his first 17 matches, ultimately earning a permanent position at the helm.
United's form has dipped dramatically since March, however, and a sixth-place Premier League finish ensured the team missed out on Champions League qualification.
Speaking to French publication L'Equipe, Mourinho insisted the struggles his former employers have encountered recently vindicate his infamous comments about his second season in charge at Old Trafford.
The 56-year-old called his second-place finish in the 2017-18 campaign one of the greatest achievements of his career and feels supporters and experts will now relate to his claims.
"In general, players may experience a certain depreciation, especially when you ask a lot of them.
"When I said that second season was fantastic, I said it because the potential and the objectives were in sync. Why? Because I pressed them, like an orange, a lot, to get there.
"When you have a squad with a profile that is very professional, very ambitious, hard-working, talented, a club structure, you don't have that depreciation."
He also appeared to weigh in on Solskjaer's nightmare end to the season, which saw United embark on a dismal run of just two wins from 12 matches across all competitions.
Mourinho doubts the Norwegian will be a long-term option at Old Trafford, hinting he lacks the qualities of a disciplinarian.
"When you're almost alone when you don't have the support of a club as a whole, then some players go towards someone who is against the coach, who is the nice guy," he added.
"I don't want to be the nice guy because this nice guy is a puppet after three months and that does not end well. But you can't be the coach who is always negative. We must look for a balance.
"In fact, the problem of the coach is the same as a teacher at school. I understood this when one day a player told me: 'Coach, please, if you want to criticise me, please don't do it in front of the other players'.
"'Why', I replied.
"Because it's an attack on my status."
Mourinho continued: "That's a hell of a change. A team is a team. A group of players is a group of brothers. The coach is there like a father, he's family, and in family, you talk openly.
"When a big player says something like that, you have to change the way you do things. The nice guy is not a coach, but you cannot be a man of permanent conflict.
"We must find a position, the one I could have with very mature squads.
"When you're not the boss, you're not the one with the power. You must be the leader."