You are both right and wrong, the players do arrive as early as 11:30 anytime up to 1:15, it depends if they are having a pre match meal at St Mary's or at home, about 10 or so will arrive up to 12 and then the rest between 12:30 and 1:15.
I am there regulary so know this to be the case,if the original poster wants the lambers and lallana's he will need to be there at 11:30 as they always do the pre match.