I don't think you can ... I thought you had an hour before first match to make changes for either. Can someone confirm. Anyways, am surprised Levine didn't get the nod ... but after what Vashy's done the last 2, I guess you have to give ML the benefit of the doubt that he knows what he's doing.
I thought it was an hour before the 1st match for the 1st match, and as soon as the first match ended for the 2nd match?
I'm not 100% sure though.
Milos' serve is just on fire right now