Yeah, they should get them on Centre. And close the roof while they're about it so there's a chance the match finishes tonight.
I'm very much in the Federer camp, so Novak's chances being harmed in any way is a good thing on that front. But putting bias aside, it is just so unfair on him (and Mannarino). He shouldn't have to come back tomorrow, when everyone else is finished, when Centre has been empty for well over an hour now. McEnroe suggested it before Federer's game had even finished!
The thing is, they try not to play too many extra matches on Centre because of damage to the court.They definitely wouldn't put an extra men's singles on, maybe a mixed doubles as they assume that it's not going to go on for hours and hours. I have my doubts whether Novak with be on Centre tomorrow, to be honest.