I hate to open this up again, but I've just read that Bayliss is saying that Ali may drop down the order and all three keepers could play.
I believe this is what you are referring to....
Sri Lanka v England: Moeen Ali to move down batting order -
http://www.bbc.co.uk/sport/cricket/46162267I also draw you to this..... in which Root says 'i don't think we can leave Ben Foakes out".
Joe Root: England captain says he has tough job to pick second-Test XI -
http://www.bbc.co.uk/sport/cricket/46153517The way I see it Root has 3 options -
1. Don't change a winning team and Bairstow doesn't play
2. Drop Curran move Mo down to 8 and Bairstow comes in.
3. Drop a spinner (likely Rashid) move Mo down to 8, Curran to 9, and Bairstow comes in.
Personally I favour number 1. Don't change a winning team. Bairstow waits his turn etc...