I think you are dreaming John. Think about it from the other point of view. If you owned Mata would you allow a committed deal that might not happen? Either they are willing to sell him because they need the money in which case they will try to get the highest price and won't lock in a price with Wenger long before the transfer dead-line, this would obvious prevent them from selling the player to a last minute higher bidder, or they don't want to sell him in which case why commit to a deal to Wenger?
I think Wenger is all too happy he can claim he ran out of time on replacing Cesc and possibly Nasri.