OzzO
.. and then?
No offense to Trap_Star but that isn't anything like the field looks for NFL games.
How about using some actual NFL Reliant photos:
The trays are visible to varying degrees but I've never seen anything that could vaguely be described as a hole...

How about field turf over dirt? Just roll it out for game day & tack it down... how, I have no idea.
Then when a concrete floor is needed, roll up the turf and scoop out the dirt.
