When Perera came in Liverpool game the first thing he did was giving instructions to some players on the field how the formation is and what the manager wants from them (you can go and watch that), Fred cannot do that right now because of Language barrier.
Lets assume that Liverpool scored a goal on us, the whole tactic will be changed to attacking, while Fred in the field there is NO WAY to explain for him what he should do and what it is his role.
I have no doubts that he has quality, but it is not logic put all the pressure on him, a new country, new league, new team, new language with all the pressure on us getting into fourth position and add Liverpool GAME pressure on him, it is too much.
I believe he will play on tomorrow's game, the coaching staff have the time to explain and train him for his role. Lets hope he will perfom well.