So first up if you have either in your lineup REPLACE them
Not sure who they bring up will matter unless you are in a really deep NL only league. Right now I would think Eric Farris or Edwin Maysonet would likely be the infielder called up. Not sure who the outfielder will be but will add names as I see them suggested by beat writers.
ETA - Brewers will call up Maysonet but second player will be 3B Taylor Greene.