Strange question- why do we have guys dressed on the sidelines but wearing pennies?

[SDDawg]

Did anyone else notice this? I thought I saw it with a couple of the QBs. Apologies if this is a dumb question, but I haven't noticed it before and was curious to know why that's the case.

[TheRef]

Did anyone else notice this? I thought I saw it with a couple of the QBs. Apologies if this is a dumb question, but I haven't noticed it before and was curious to know why that's the case.

They signal in the plays