The Italian side were thumped 6-1 by minnows Bodo/Glimt in the Europa Conference League last week.
A furious Mourinho claimed after the game his fringe players were not good enough and only has '13 players' in his squad up to scratch.
The former Chelsea, Manchester United and Tottenham boss dropped Amadou Diawara, Borja Mayoral, Gonzalo Villar and Bryan Reynolds from his squad for the next two games.
They were absent from the 0-0 draw with Napoli on Sunday and were not picked again for Wednesday night's clash with Cagliari.
Diawara's agent hit back at the claims and actions of Mourinho in stunning comments.
Daniele Piraino told Tuttomercatoweb: "I don't understand the message he's trying to get across.
"Is Diawara being made a scapegoat? Is he being made to pay a heavy price for an error? Or is an attempt to force the club into acting in the transfer market?
"If it is for these reasons, rather than just poor fitness, or he feels the player is unable to understand the tactical requirements of the coach, then I think Mourinho is creating an uncomfortable situation.
"It is inexplicable but Diawara will adapt. Amadou is an exceptional professional."