At his pre-match press conference ahead of United's Champions League group game with Juventus in Turin, Mourinho was reluctant to speak candidly about the claims levelled at City.
"The storm is outside," Mourinho joked, referring to the Turin weather. "Is raining a lot, we feel at home.
"I have thoughts from a few years ago but I keep the thoughts to myself."
In 2017, Mourinho said: "The FFP authorities, they have big work to do. Big work to do, because probably there are some strategies of disguise but I have to believe that the FFP [authorities] are going to have difficult work to do."