Monday Night Football didn’t have on disk protection but a code you have to look up. First let me know you have do wait for the game to load through about 4 or 5 intro screens before you even get to the code screen.
See the screen below with the couch looking guy. There is a Passcode on the bottom left. Look up that code on my PDF code sheet here: Monday Night Football CODE SHEET
The Passcode on this screen is 24 so you need to enter in ’59’ and the game will then load.