Both nations plan to defy FIFA's decision that wearing poppies would be in breach of its rule that forbids teams from displaying political symbols, risking a potential points deduction.
However, Glenn pointed to the fact that English clubs wearing poppies on their kits at the weekend was also technically a breach of FIFA's rules and vowed to fight any sanctions that football's governing body may impose.
"We think they're interpreting the rules wrongly. This is a law-of-the-game issue, not a FIFA competition issue. So, I'm very confident that our legal position is right, our moral position is certainly right, and – you know what – there are bigger things in the game for Fifa to worry about," Glenn is quoted as saying by The Guardian.
"We'll contest it strongly because we believe – we've had QC opinion on this – our case is absolutely rock solid. So, good luck. We had a row with them in 2011; we thought we'd got over it. Unfortunately, with new personalities coming in there, they felt they wanted to make a bit of a stand, which is very disappointing.
"In the event if there were something [a fine], I'm sure we could persuade them to divert the finances for the Royal British Legion. But I'm very confident it won't come to that."
England previously wore poppies with FIFA's go-ahead during a friendly with Spain in 2011.