Was your lineup set up exactly like this?
PG: Garbett Bertinelli Bertinelli
SG: Monreal Monreal Monreal
SF: Dodd Tkautz Tkautz
PF: Faggiano Mpravos Mpravos
C: Katidis Zuleta Zuleta
Strictly Follow Depth Chart
Let Them Play
That should have worked, even with a blowout lead, and left Monreal in for the whole game (or at least until he fouled out). Set up like this, Monreal should have definately started the fourth quarter. I have had a problem in the past where my "whole game" player was inexplicably taken out at the 47 minute mark. I have never seen my "whole game" guy not even start the fourth quarter though. If you followed the above exactly, and still had Monreal sub out after 3 quarters, I have no idea how that could happen (unless he was injured or had fouled out).