Should I contact this PI now or later?

[charp]

Hi all! 

I am about to start my PhD program at the end of the month (yay!) and am currently looking at potential  labs/PIs for my first research rotation. The program has sent out a list of professors that will be accepting rotation students for each of the 5 rotations this year. They also included a list for professors that aren't accepting students and a list titled "Unclear whether the following faculty are accepting rotation students". The lists will be updated between each rotation, so some labs might be open to students at a later date than planned right now. 

One of the PIs whose research I am extremely interested in is included in the "unclear" category. Should I send an email to him now expressing my interest in his lab and ask about any possibility that he might be taking students at any point this year, or wait to see if his status changes after a rotation or two has already passed so I don't look over-eager/don't respect that he may be undecided at the moment?

Thanks!

[PsyDuck90]

I don't think there is any harm in asking.