Yes, Silva’s performances will dictate how often he plays. And if KDB stays fully fit that will help Silva.Based on his useage of Silva and Fernandinho last season, when we were all screaming about resting them but he just continued to play them 3x a week, I think Pep will use Silva as much as possible until he completely runs out of steam.
I think best case scenario for Phil is something like Bernardo's first season when he comes off the bench almost every game and starts about 5-10 league games, 7 or 8 cup games and a couple of CL games if the draw goes our way.
Which would mean 40+ appearances and 15-20 starts which at 19 years old would be loads.
When iniesta was a year older than Foden he made 38 La Liga appearances for Barca, but 25 were from the bench. If Foden has a similar season he will be doing exceptionally well.