Like roonster said, we have 10 (Rashford makes 11 but he's still underage). Grant and Young may not be here that much longer due to age though.
Registered home grown players at the 'big six' (i.e. not including Foden, Rashford):
Manchester United - 10 (Andreas, Grant, Jones, Lingard, Lukaku, McTominay, Pogba, Shaw, Smalling, Young)
Chelsea - 9 (Barkley, Cahill, Christensen, Drinkwater, Fabregas, Green, Loftus Cheek, Moses, Piazon)
Arsenal - 8 (Bellerin, Holding, Iliev, Iwobi, Jenkinson, Martinez, Ramsey, Welbeck)
Liverpool - 7 (Clyne, Henderson, Lallana, Milner, Ox, Randall, Sturridge)
Tottenham Hotspur - 7 (Alli, Davies, Kane, Ogilvie, Rose, Trippier, Winks)
Manchester City - 4 (Delph, Sterling, Stones, Walker)
Can't see Smalling going anywhere. The one defender we've been able to rely on to keep fit the past couple of seasons whereas most of our other centre backs have had various issues. He'd be the last of the centre backs to be sold IMO.
That is what Red_toad is saying in reply to FootyGirl - we won't get money for him so he can't be sold. He'll leave on a free.