I asked my DH, and he still doesn't think you should have any problems at that altitude. Everyone is different, though.

We didn't even have trouble at Bryce (8000 ft), but we'd been out west for awhile by the time we got there so had probably acclimated somewhat. We did a couple of strenuous hikes there with no issues, though.

I think worrying about it might tend to make things worse...the mind is pretty suggestible. Was hoping some others who had gone from lowlands to Moab would chime in...maybe they still will.