According to Kei's blog today, he was sick just before this tournament and had to be in bed for four days. Apparently his temperature sored to 39C!
So he was just recovering when he played R1. It seems he's fine now and he also enjoyed playing doubles with Soeda on Wednesday, although they lost. It was his first doubles match in nearly two years, and he hopes to team up with Go again some time. (They also played together at Japan Open in 2007.)
Anyway I was able to take further rest yesterday and can give his best in today's match(es)!