Most wrasses will hang out in the substrate. My Yellow Wrasse hid for ~5 days before he started coming out. Now he comes out like clockwork an hour after lights on and an hour before lights off. I had a highly agressive hawkfish for a while too and for about 4 days straight he was in the sand and didn't eat. I thought he was dead but he's a trooper. Give it time and he'll come out around midday or so when he's ready.
