Playing vs AI and sleep mode

Hello, I like a lot Xmage to play against AI, especially with the rollback feature that no other mtg games seem to have, but it has one main issue: if I have to go and put my computer in sleep mode, the game is lost when I come back because of the disconnection with the "server", a problem I obviously don't have with other mtg games. Is there anything I can do to avoid that ?