I sort of feel Dan Cox should definitely be nominated - for tenacity, after what he's been through, and some very good results.
But he's not one of my gang of faves..... so, if it were only one nomination, I might keep it in hand....
I have nominated more than one player in the past, sometimes in the very same post. I am sure you can nominate as many as you want.
the rules on nominations are that there are no rules on nominations!
Anyone can nominate anyone they feel deserves it and as many players as they wish - as Bob says, several people have nominated more than one player in a given month.
And it can be for any reason - winning a big tournament, playing above their level, a month of sustained good form, a big upset, a team performance of note, perhaps for non tennis reasons or non on the court reasons (eg Jamie last month was nominated in large part for his role in BotB).
So go ahead and nominate!
For the record, let me know in response if you want to nominate Dan Cox - all I ask is that there is an official record and then I will build and keep a list in this thread as the rest of the month progresses.