The Spanish-speaking contingent within the squad were said to be particularly unconvinced by Rosenior, with leadership meetings described as becoming "increasingly quiet" as his tenure unravelled.
Video footage of players apparently snubbing his backroom staff circulated within the club on a near-weekly basis, including one clip of Wesley Fofana ignoring assistant James Walker after Saturday's defeat to Manchester United.
Sources described players "jokingly" mocking Rosenior's use of what they termed "LinkedIn language," while some also made comments about his decision not to wear his glasses at training in what was described as an attempt to "look tougher."
Rosenior initially leaned on the blueprint left by Enzo Maresca when he took charge in January, but began to lose the dressing room when he attempted to implement more of his own ideas.
The final straw came after his post-match interview following the 3-0 defeat at Brighton, in which he accused the squad of lacking desire and professionalism. Players who heard those comments were described as being "close to mutiny," and the sacking followed the next morning.
A source close to Paris Saint-Germain also told the BBC that Rosenior's approach across the two-legged Champions League tie — an 8-2 aggregate defeat — was seen as "too open," with Chelsea repeatedly exploited in behind.
Not every account of Rosenior's tenure was negative. Most players regarded him as a decent person, and he was said to be more popular with the English-speaking members of the squad.