He won't be there because he hasn't trained for City in 3 weeks or more now. He's back in London and hanging out with Nelson and their mates.
I suspect he's informed the FA and City that he wants to terminate his contract and that Arsenal (or possibly another club but, in all honesty, that seems very unlikely at this point) are trying to negotiate a compensation fee with City. If they can't then it'll go to a tribunal and the fee will be set.
I've seen a few rumours around that he has trained and is possibly still training with Arsenal, which is allowed under the terms of his scholarship contract, provided he's followed the correct procedure in terminating his contract.
Unless all the signs are pointing the wrong way, I'd be very surprised if he wasn't announced as Arsenal player in the next few weeks.