If you have daily starts, I'd take Francouz. He's going to be the guy playing until Grubauer returns since there are no back-to-backs.
If you need someone for the whole week, see if Koskinen is set up to start 2 or just 1 game this week. If it's one game, take Hart. If it's 2 games, and one of them is Dallas, take Koskinen.