If they were England, fair enough. I believe players playing for their country should sing it, but tbh now there's just not much point. Now it just seems more of a national thing than it is.
But considering the FA insist on having it between two teams who wouldn't be where they are without people from other countries, from a league made up of primarily foreign players, it seems stupid.
Chelsea had 3 English players starting. That's like, 8 who wouldn't be singing it anyway.
Suppose the fans took the same stance.