I think If he will win in singles they will withdraw from doubles. Grisho plays not before 16.30, for you 17.30. This is the third match on center court, the first match will begin at 13.00(local).
I don't know, SF is too much to withdraw from doubles. Maybe it depends on how the single match goes. If it is an easy win in 2 sets or a lost, he will push in the doubles but if it is a hard win, maybe will skip the doubles...who knows! If takes both matches would be better because the doubles final is after the singles one on Sunday (if he goes that deep) and this will make winning both titles theoretically possible. Maybe that's why they scheduled both matches in one day tomorrow.